How to Prepare Wood Panels for Painting – Using Acrylic, Oil and Other Artist Mediums

by | Mar 14, 2017 | Blog | 116 comments

Why Use Wood Panels for Painting

There are many types of surfaces that painters can use for fine art painting. Canvas attached to wood stretcher bars have been used for a long time, and wood panels even longer. Wood is stronger and more durable then the fabric of canvas or linen, and is therefore more archival. Contemporary painting techniques such as pouring paint (i.e. Jackson Pollock) and gluing collage-style are much easier with a sturdy level surface such as wood. (By the way, Pollock did not use wood for his paintings).
Proper preparation of an artist support is essential for producing long-lasting artwork. Raw wood panels need to be sealed prior to priming and painting, to keep moisture from getting to the wood which causes warping and other damage. So once you purchase a wood panel you need to do two important steps before painting: seal to keep out moisture, and then prime to strengthen adhesion between the paint and wood panel.


What’s the difference between hardboard and Masonite

I get asked all the time about the difference between these two terms for wood panels. Click here for a great article that clears up any confusion between the two.


Where to Get Wood Panels

If you are lucky enough to have wood working machinery, you can make wood panels yourself. Otherwise you can purchase commercially made wood panels from art stores and online artist supply sites. Ampersand makes great panels of good quality. They are the only commercial panel company that I know of that properly seals and primes their panels called Gessobord.  Less expensive versions are available through Dick Blick and other online sites. Commercial panels can come with or without cradled sides (separate wood applied to the panel to add depth to the sides), and with or without coatings (such as gesso or other primers).

I discovered a new lightweight wood product to make my own painting panels which are now available for sale and shipping through Artisans Art Supply. My panels are called (no surprise!) Nancy Reyner Custom Artist Panels. The best part is they are very light in weight. I work in large sizes and this makes it easier to work in my studio and much cheaper to ship them to clients and galleries. As an example, my custom panel measuring 30″ x 40″ weighs 7.5 pounds. The same size panel from Ampersand weighs 11.4 lbs. Quite a difference!

I have two issues with commercially made wood panels. I like to work large and in sizes that are not standard. Commercial panels only come in standard sizes, with maximum lengths around 40″ per side. If you want a non-standard size or something larger than 40″ there are not many options. Some commercial companies offer custom panels, but these may take up to six months (not kidding) to get it to you. Commercial panels mostly use hardboard for the painting surface which can get very heavy in large sizes.


Why is it Important to Prepare A Wood Panel

Oil painters must seal wood to stop any acidic oil in the paint from penetrating into the wood support, which can cause wood fibers to rot. While acrylic painters do not have this same issue, sealing is still an important step for using acrylic paint on wood, to eliminate Support Induced Discoloration (SID). SID is a phenomenon that occurs uniquely with acrylic paints. Supports naturally contain impurities that can cause an amber yellow discoloring to any light colored or clear acrylic layer that is applied to the wood unless the support is sealed properly. More about SID on GOLDEN’s website.

Sealing (sometimes called sizing) reduces chances for the wood to warp due to shifts in humidity, and therefore adds an important archival process to your artwork regardless of which painting medium you choose. Sealing also provides an easier surface to apply subsequent paint layers.

Sealers are often confused with primers. A sealer protects the underlying layer or material. It usually needs to be glossy (or non-absorbent) to properly protect the surface by creating a barrier. A primer is a foundation layer that strengthens paint adhesion onto the support. Generally a primer refers to a coating that prepares the surface for the acceptance of paint. Gesso is a primer and not a sealer. Gesso, when applied, has a satin or matte finish, is absorbent in nature, and therefore will not adequately seal the wood unless multiple applications are used – and this still may not seal.

A general rule is to apply at least two coats of sealer directly onto the raw wood to protect the wood. Then over these sealer layers when dry, apply primer to (1) enhance adhesion (2) return tooth to the surface, and (3) whiten the surface for optimizing paint colors applied over it.


Instructions to Prepare Wood Panels

(1) Clean off any dust or debris from all exposed areas of the panel including the cradled sides and panel back, first using a vacuum or air pressure if very dusty, then wiping clean with a microfiber cloth (or other lint free cloth) slightly dampened (with water).

(2) Lay the panel flat on a table, propping it up several inches on all four corners with jars, wood props, etc to allow for wiping away any drips, and ease of application.

(3) Apply a glossy acrylic medium over all exposed wood surfaces. GOLDEN’s GAC100 is made especially for this purpose. It’s special thin formulation of polymer acrylic, applied over the wood, soaks in quickly and minimizes brushstrokes and texture. GOLDEN has recently changed their advice saying that their Acrylic Gloss Medium works better as a seal then their medium called GAC100. I still prefer to use the GAC100 because it is thin and doesn’t create brushstrokes like the Gloss Medium. GOLDEN still says both work fine. You can also opt to use a commercial stain sealer like Kilz found in home improvement stores.

Tip: Let one surface dry fully before flipping over to seal the reverse side. Drying times can vary. When dry to the touch with no tack, it can be flipped over without sticking to the table or other props.

(4) When all exposed wood areas are sealed and fully dry, the wood will feel very coarse. That is because the wood grain gets raised with this first coat of sealer. Lightly sand all surfaces to smooth them using a 220 grit or fine sanding block. There is no need to heavily sand, just an easy swipe with the sandpaper will suffice.

(5) Wipe the surfaces clean with a slightly damp rag after sanding or vaccum, then apply a second coat of sealer. Usually two sealing coats are sufficient, making the wood appear slightly satin or glossy in sheen. Optionally apply more coats if you desire a more saturated seal.

(6) Once you finish applying all sealer coats and it is dry to the touch, I recommend to apply one or two coats of a primer, such as an acrylic gesso, especially to the front surface to regain surface tooth. Priming your panel, regardless of which paint medium you plan to eventually use, will add a second archival process to your artwork, by strengthening adhesion between your first painting layer and the primer. Opt to prime all surfaces, including the back and sides, for a clean white professional look. However, all you really need to do is prime the panel face that will be painted. To summarize you want to seal all exposed areas of wood, but priming can be just applied to the front face.

For acrylic painters, one coat of a better quality gesso, such as GOLDEN’s Gesso, will add adhesion strength between the sealed wood and your first layer of acrylic paint. Lesser quality primers are sufficient for use with oil paint, as oil seeps into the layers differently than acrylic. The lesser quality primer, though, does not have a high pigment content for extra adhesion strength that acrylic paints require.

Once the gesso is dry to the touch it is ready for applications of acrylic paint. To apply oil paint instead, wait 1-3 days or more.

Important: For this blog article I am offering information for fine art paintings that will be stored and/or displayed INDOORS. For information on outdoor projects, such as murals on wood, read this article.

To order custom panels
More info on preparing panels

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  1. Gen Yoder

    Thank you for your article and descriptive comments.
    What would you recommend to seal acrylic paintings on a wooden chair or viola? Thanks!

    • Nancy Reyner

      Dear Gen,
      My favorite product to glue is Golden’s Soft Gel Gloss. You can use this same product to apply OVER the paintings if they are painted directly onto the wooden support or furniture. I suggest trying it out on something you don’t care about first as an experiment to make sure you like the results. The gel is thick, so for sealing you can dilute it with up to 40% water so it applies smoothly. I also recommend that for functional use, like furniture, the best sealers would be commercial grade products like high grade polyurethane made for sealing wood that will get alot of use and physical contact.

  2. Michael


  3. Michael

    Great info!!!

  4. Renee

    I paint with acrylic paint. I use white hardboard.
    I applied gac100 and after I applied the gac100 the surface was granulated and that never happened before and then I applied gesso
    When I started to paint the whole surface was pealing I could peel off the whole surface of my board. Can you help

    • Nancy Reyner

      Hi Renee,
      I’m sorry to hear you are having difficulty with your surface prep. It sounds like there is an issue with your white hardboard. Since hardboard is wood, and is naturally brown – not white – it would be good to call the manufacturer of the panel to find out what they are using for the white coat. It may be that the white hardboard is not compatible with acrylic. It also may be that particular board was defective. Try it again on another white hardboard, but this time wipe the board clean with a soft no-lint rag and denatured alcohol. Sometimes panels come wrapped in vinyl plastic. When heated (maybe during shipping in a hot truck) the vinyl can imprint onto the white surface, and cause it to become incompatible with acrylic. There is one more possible cause to the granulation. If you applied the GAC100 with a rag or paper towel, this cold have lint that got deposited onto the surface and “glued” on with the GAC100. Try it again but cleaning it first as I mentioned, then use a soft brush to apply the GAC100 – and apply it gently without scrubbing the medium into the surface. Let me know how it goes.

  5. Dianna

    Hi Nancy, thank you for this very informative post as well as the helpful info in the comments!

    I am a novice and didn’t know I needed to seal and prime wood panels before using acrylic paint on them. I now have a couple relatively small panels (9×9 and 12×12) that I’ve painted on and really like. Is there any way to “save” these after the fact?

    Another question — most of the primers I’ve seen are white. I would like the backdrop of the painting to be the natural wood grain of the panel. Are there any transparent primers out there?

    Many thanks!

    • Nancy Reyner

      Hi Dianna,

      When using small sizes as you have indicated, you may be able to get away with not sealing. Sealing the backs and sides (if cradled) are important to keep the wood from warping. Wood will warp – it just does. So it’s always a good idea to seal front, side and backs before painting, to make sure the wood stays flat. Once you paint with acrylic on the front face of the wood, you are in a sense sealing the face with this paint layer. So the front of your painting, even if you didn’t seal and prime before painting, should be OK. It’s the back of the painting that I’m thinking is still raw? If so, it’s easy to fix. Just flip your painting over on its face, using a clean surface. Apply two coats of sealer (any gloss acrylic medium is fine) onto the back. Let the first coat dry to the touch before applying the second. If after the first coat, the wood raises to create a texture, you can lightly sand it to smooth it out, to make applying the second coat easier. If you want to keep the wood grain showing without covering it with the opaque white gesso primers, then don’t bother priming. Once you seal the wood with two coats of sealer, you can apply acrylic paint directly to that. Primers are an extra step to make sure the first painting layer adheres strongly. Since you already apply two coats of an acrylic sealer, the first painting layer will adhere well without the primer. I like to prime when I can, as an extra layer just to be on the safe side. But you can always skip this step if you don’t want to cover the wood grain. Another idea is to apply an acrylic matte medium over the two glossy sealing coats. Transparent primers are available, but honestly they are mostly matte mediums, which contain a white powder to make them matte. This white powder in the product will also act like a primer. This will add some adhesion strength, but actually is only needed if you don’t want to paint on something glossy. Hope this helps! Nancy

    • Dianna

      Thank you, Nancy, this is very helpful and appreciated. I’m learning so much.

      I am glad to hear it will be OK if I seal the back of the painting. There is still a small amount of exposed wood on the front because I didn’t paint the surface in its entirety (I wanted some wood to show through). Should I try and varnish over the front side or just leave it alone?

      Thanks again.

  6. Sam J


    Thank you for this insight on prepping panels.

    If an artist already has panels that have been treated and painted on, do you suggest a certain technique/process for adhering them to a wooden frame backing?

    Thanks in advance!

    • Nancy Reyner

      Hi Sam,
      Thank you for your comment. If the panel has already been treated and painted, then that deals with the top face. The back is another issue and has nothing to do with the top, although the back should be sealed too and not left raw. If you want to adhere the painted panel to something else, then you can use a variety of glueing methods. Basically you are glueing wood to wood, so a wood glue should work well. Apply the wood glue, clamp in place while drying following instructions on the glue’s container. Hope this answers your question. Let me know if I’m missing something here.

  7. Margaret

    Hello – I really like your work. I am interested in learning how to paint on wood. I’m working on building a portfolio. Any help you can offer would be great. Any books or reference materials you can suggest.


    • Nancy Reyner

      Hi Margaret,
      I also paint on wood. I use wood panels. They are available in art and hobby stores. You can also get them cut at hardware stores from sheets. In this article I offer many ways to find them, and also how to prepare them from raw to sealed properly for painting. Basically you can paint anything in any style, using any mediums, and any subject matter. The wood is merely a painting surface, just like canvas would be, or a wall, or fabric. So in answer to your question about help, this article will get your surface prepared properly, and then anything goes. This means any and all books, videos and courses on painting. If, however, you were interested in ways to use acrylic paint, I highly recommend my Complete Guide to Acrylic Painting. It has all four of my books, 30 videos and lots of supplement material. This may be all you need to paint on wood (or anything else) using acrylic. Here is a link for more information on that course.

  8. Joseba Barriola

    Excellent tips. Just found your page and I’m begging for to start a wooden sculpture idea and was having trouble painting some wooden cubes. One question where can a buy some premium wooden cubes to make some sculptures ?

    • Nancy Reyner

      Hi Joseba, Your project sounds intriquing painting on wooden cubes. I suggest instead of looking for them already made, to contact a wood worker or cabinet maker in your local area, and ask for a custom construction. A wooden cube custom made should not cost much, and then you have your own resource whenever you need them. You can pick the type of wood, size and how its finished. I doubt you can find them already made, in a raw state, without someone painting on them already.

  9. Elaine D.

    Just came across your site looking forward for good info. Just started acrylic painting.

    • Nancy Reyner

      Hi Elaine,
      Thank you for your comment, and glad you are finding my site helpful for your painting.

  10. Katie Whelan

    I’m not sure if you can help me but I recently graduated with a Fine Art degree and I’m trying my luck at freelancing.
    I’ve done a few jobs but this one has me scratching my head. I’ve been asked to paint an album cover onto a garden fence panel. The panel obviously sits in the garden in all weathers and so I’m unsure what the best materials are – spray paint? Acrylic? do I need to prime it first? Do I need to gloss it afterwards so it doesn’t peel? I have one chance, one fence panel, helpppp please x

    • Nancy Reyner

      Dear Katie,
      While there is absolutely nothing you can do to keep paintings lasting forever outdoors, there are many things you can do to keep it lasting for awhile. The more you do to keep it protected the longer it will last. Again – never permanently. So make sure in your contract it states very clearly that you are not responsible for weather damage and normal wear and tear from being outdoors. For exam pile, you can put your client at ease by telling them you offer a touch up for weather damage after 1 year, but after that you won’t…or some other offer you are comfortable with.

      In the meantime, here are some suggestions. Find out what the fence is already painted with, and if it is sealed. You will need to make sure subsequent layers use the correct materials. For example, if the last coating on the fence used an oil based sealer or paint, then you need to continue with oil-based primers and paints. You want to make sure your paint adheres well to the fence. You will need to first apply a good primer meant for outdoors, then use acrylic paints but select colors that are extremely light-fast (Golden has charts available for this), then you will need to seal your finished painting with UV protection, using several coats. Here is an excellent article on all the steps for outdoor murals from Golden:
      Hope this helps!

    • Katie Whelan

      Thank you so so so much!! I’ll send you a picture when it’s finished x

    • Nancy Reyner

      Great! Looking forward to it.

  11. Patricia

    Hello Nancy,
    After using the seal and gesso primer for acrylic painting, what kind of varnish do you recommend?

    Should the seal and gesso be required for wood AND canvas if using spray paint? Are there different types of varnish when combining spray paint and acrylic?
    I appreciate your help

    • Nancy Reyner

      Hi Patricia,
      Once you seal the wood all over – front, back and sides – on any exposed areas of wood, you can then apply gesso (primer) on the face of the panel where you will be applying your painting. You can apply it all over if you want, but the important area is on the front face.

      I want to emphasize that sealing the wood has NOTHING to do with what you will paint over it. Sealing the wood keeps moisture from entering the wood which can warp the wood. If you don’t want the wood to warp you MUST seal. Gesso or priming is the next step which adds strength to the adhesion between the sealed wood and your first layer of paint. You don’t have to do this step, but primer is always a good idea because it will keep the paint from flaking off if the painting gets stressed. Paintings get stressed while shipping, with temperature and humidity changes. Again this step doesn’t change if you are using spray paint, acrylic, fluids, ink, oil. All these mediums could use some extra help in adhering to the sealed wood panel.

      Once your painting is dry (oil paint needs longer drying times) then you can apply a top coat of varnish. For the top coat, I suggest using an archival varnish. These have UV protection, do not yellow, and are removable for cleaning purposes. If the product label does not offer instructions on removing the varnish, it is not an archival one, and will not give complete protection.

      I use several types depending on the project at hand. If it is a small size and has alot of texture, I will spray using Golden’s Archival Varnish Spray Gloss. If it is acrylic and smooth or not too thick in texture, I like to brush apply Golden’s Polymer Varnish Gloss. This is non-toxic so I like to use this one whenever possible. This will NOT go over oil paint, and should NOT be applied directly on unsealed metal. For oil paintings I like to use Gamvar, or Golden’s MSA Varnish Gloss. If your painting uses both spray paint and acrylic you can use the MSA, Gamvar, or Archival Varnish. I would not use the Polymer Varnish or it may bead up over the spray paint if not compatible.

  12. Nicole

    Hello Nancy,

    I’m so happy I found your post as I’ve struggled for weeks knowing how to tackle prepping my next painting!! I paint with oils on cradled birch panels. Previously, I only used Gesso (but have since learned that that doesn’t really work as it’s only a primer. And I am not crazy about the painting surface after the gesso has dried). I saw you mentioned Kilz as a sealer. When I researched the product, I saw that there was a “Kilz Klear sealer and bonding primer”. Would this be ok to use as both the sealer and the primer? Would I then be able to paint with oil paints on top with solid paint adhesion?

    I’ve also done a little bit of reading and came across a YouTube artist and teacher that recommends using Rustoleum primer as a primer for wood panels. Would I use the Kilz sealer and primer and then the Rustoleum primer over that, and then once completely dry, follow with the oils paints? I know these are commercial products and not fine art products but I was hoping you’d be able to direct me.

    • Nancy Reyner

      Hi Nicole,
      Glad you found this post helpful! Your question about Kilz is a good one. I am not familiar with that product but do recommend you contact Kilz tech department and ask them directly. It does sound like it would be OK to use as a sealer and primer – two in one product. I have a feeling this is a toxic product, though. If it says to clean brushes with turps then it is solvent-based and therefore toxic. Why not try an acrylic gloss medium, or the Golden GAC100 I recommend. These are fine art products so they would be better suited to artwork, and are non-toxic water-based products. They will be easier to use, easier to clean brushes, and will work well under oil. Since oil seeps into surfaces more deeply then acrylic, and can harm materials when it comes into direct contact, I recommend applying at least 2 coats of clear sealer (Gloss acrylic medium or GAC100) and then at least 2 coats of acrylic gesso. This way the oil paint won’t go through the gesso and sealer and come into contact with the wood itself. I am not familiar with Rustoleum Primer either. I doubt you would need two different primer products. One product to prime should suffice, but as I said before apply at least 2 coats. Hope this helps.

    • Nicole

      Thank you so much! I really appreciate it! 🙂

  13. Naomi Naumann

    Hello Nancy, so I work primarily on watercolor paper that has been mounted with matte medium to cradled panel. I’ve always read that giving my panel a couple of coats of gesso was enough to seal it but I think I’m going to get some gac 100 and start using that before I gesso. However, right now I have a bottle of liquitex gloss medium & varnish and I was wondering if you thought that might be a suitable substitute for now. I was also wondering about sealing the back sides of my panels. In the past I’ve often sealed them with polyurethane. I know it has a tendency to yellow but since it’s the backside I don’t really mind all I’m trying to do is protect the wood from moisture. Do you think this is a suitable to protect the wood? It’s just that I often work very large (I’m currently prepping a 3ft by 5ft panel) and polyurethane is a lot cheaper than art mediums. Thanks for such a well informed article, it can be quite the challenge to find good info on these kinds of topics.

    • Nancy Reyner

      Hi Naomi, I agree that sealing the wood panel is a good idea, and will help reduce warping in the future. Gesso does not seal. It is a primer meant to enhance adhesion. In other words, applying gesso to a surface will help the next layer of paint stick better. A sealer means it keeps moisture from getting to your surface, which is part of what makes a panel warp. Acrylic gloss mediums will generally work like Golden’s GAC100, so I do believe you can use your Liquitex medium. Sealing all sides of the wood, so that moisture will not enter the wood is recommended, so that means sealing the back and sides as well as the front.

      I am guessing that Polyurethane will work too. There are a variety of types, and most of them commercial, not meant for long lasting fine art works. So I caution you with this product which may not give the best results.

      I am not comfortable giving advice on polyurethane as a sealer for the backs, since I have litte experience with it, and therefore recommend you contact Golden’s technical department. They are very helpful and will give you better advice with this.

      I paint large too, with most of my paintings 4′ x 5′. I try to avoid spending money unnecessarily, but with the case of fine art paintings, I do not want to risk having the painting sold and then return to me with issues. Warping is an issue with little solutions. Therefore I tend to use all fine art materials for my work. If you actually measure how much medium it takes to seal the backs of your painting, and for 2 coats to be sure, and compare this with how much polyurethane, I wonder how much difference in cost it actually is. Just a thought….

  14. Jerry Zindler


    Thanks for all the great information in this article. I was wondering what scrap types of wood could possibly be used: i.e. fir 2 by 10, pine 2 by 10, or plywood that one might find at a construction site to help defer costs?

    • Nancy Reyner

      Hi Jerry,
      Good question. Finding wood at a construction site is a way to save money. However there are some pitfalls. There are two types of wood used in building – finish grade and construction grade. Finish grade are for cabinetry and other interior needs, and are rarely left for the picking at sites. Instead more commonly found left at sites are the construction grade type woods. These woods may still contain moisture if recently cut, and therefore require time to dry out to become stable, which may take about a year per inch thickness. Plywood doesn’t shift as much by the time its internal moisture has dissipated, so it would not take as long to dry. So that’s the first issue. You need to make sure the wood moisture has disipated before using the wood to create a painting support. There is a second issue. Once wood dries it usually shifts and twists out of shape. This means you may need professional woodworking tools and techniques to take the twisted wood and turn it into a usable painting surface.

  15. Charlene

    Nancy, Today I finished prepping all of the large cradled boards in my studio as per your instructions. They are safely stored in the closet waiting for the prefect images. Thanks to you and your process of taping the edges with cellophane tape, my edges came out beautifully. My husband’s terrific work and my finish are exactly as I wanted, clean and crisp. The studio will now have a good stock of Scotch tape. Thank you for sharing this process.

    • Nancy Reyner

      So glad to hear! Thank you for letting me know.

  16. Charlene

    Nancy, thank you for the clarity regarding the GAC500. I was read the online uses for all of Golden GAC products, as I was only familiar with GAC100. I look forward to trying your method.

  17. Charlene

    Hello Nancy, My husband is currently building large format cradled birch plywood panels for oil painting. I will use these for portraiture and figure using cold medium. The plywood was purchased from our local DIY store. I have prior knowledge of sealing with GAC100 and gessoing with commercial brands of smaller cradled birch panels. For those I taped the cradled edges up to the top of the panel. After sealing I prepped the top panel with gesso. When a beautiful portrait was complete, I took the tape off to find the gesso and oil paint had seeped onto the clear birch sealed cradle. This piece had to be framed. I truly wanted the clear birch to show for complete portrait without framing. How can I prevent this? The 1/4″ of DIY plywood is thicker than the commercial brand I bought and I am not sure if I should cover just the cradle birch excluding the 1/4″ plywood. I would need to finish the 1/4″plywood with gesso and paint application, leaving the cradle clear? Your thoughts would be greatly appreciated. I am about to start a production line prepping his beautifully crafted boards. I would like to do them all the same if possible. Thank you, Charlene

    • Nancy Reyner

      Hi Charlene,
      It sounds like you are sealing all the exposed wood properly, and then taping off the sides so you can just paint on the front face, with the intent to keep the sides clear, only sealed. Your issue is to keep the taped edge clean, correct? Here are some suggestions that will help. First, do not keep tape on for long periods of time. It loses its sticking power enough to create seepage as you have experienced. Tape it for a day or two, and then remove the tape after your painting session. The next time you will paint just retape it. There is an alternative to this taping and retaping but I wanted you to have a couple ways to work. Once you apply the tape to the cradled sides (I am assuming you are waiting at least three days after sealing so the seal coating is fully dry) you can apply Golden’s specialty medium called GAC500 with a small brush right at the edge of the tape where it will come into contact with paint. In other words you don’t need to apply the medium on both sides of the tape. The medium is strong and thin and will create a clear barrier so that paint will not seep under the tape edge. Try this out on a small experimental panel before trying it on one of your paintings. I also suggest to use scotch tape instead of the blue painter’s tape or masking tape. Scotch tape is thinner then masking tape and makes a cleaner edge. I am not understanding the second part of your question, regarding the 1/4″ plywood. Just add more detail so I can understand your issue more clearly and I’ll be glad to answer. Hope this helps.

    • Charlene

      Thank you Nancy, you answered all of my questions. The unsealed/unprimed cradled panels commercially offered have a birch veneer 1/8″ side reveal for smooth topped cradle. The DYI home stores birch plywood is also a veneer with MDF layers equaling a 1/4″ with rough edges. My husband has handled the problem since I emailed you. He added wood filler in a light tan color, which he sanded to a smooth finish. I would like to preserve this edge with the unfinished cradled. I am assuming the GAC500 would be in place of the white gesso for oil painting?

    • Nancy Reyner

      I mentioned the use of GAC500 specifically for keeping your tape edge clean. That is one of its main purposes. I would definitely not use it as a primer. I recommend using GAC100 as a sealer on all exposed wood areas, then use Gesso to prime the top face of your surface. Then tape off the edges using the scotch tape I mentioned, Just at the edge of the scotch tape that touches the face you apply the GAC500 to keep the tape edge sealed so that you don’t get any paint seeping into that edge. Make sense?

  18. Carolyn

    Thank you so much!

    • Nancy Reyner

      Carolyn you are very welcome!

  19. Carolyn

    Hi Nancy, This post is quite helpful as I am planning a new acrylic painting series. I have a couple of questions.
    First, I am painting on small panels (4×4 and 6×6 inches). Is it necessary to seal the back of these cradled panels with acrylic gloss medium? My understanding this is to prevent warping. Is this a concern for such a small-sized cradled panel?
    Second, I am working with deep cradled birch panels and intend to keep the sides unpainted to show the birch wood. Should I coat the sides with gloss medium (2 coats) and use satin acrylic varnish, or just use the varnish alone?
    Thank you!

    • Nancy Reyner

      Hi Carolyn,
      That’s a good question. The small size panels will probably not warp. However, just to be on the safe side, I would seal ALL exposed wood, even on the back with some type of gloss acrylic. I learned the hard way that sometimes cutting corners does not pay off.

      For the sides I would seal with gloss medium as you mentioned, and then apply some type of satin or semi-gloss medium. Varnishes are different then mediums. Varnishes have special qualities like UV protection, and are for protecting the face or image of the painting. I usually won’t use varnish on the sides for several reasons: 1. Varnishes tend to take a bit more care to apply while mediums are easier to apply. 2. You won’t need UV protection on the sides. 3. Varnishes are more expensive then mediums. Hope this helps!

  20. Andy

    Great info, thanks! My question is regarding the back of the wooden panel.. after sealing with GAC100 and gessoing, in your opinion do you think the back then also must be painted with an acrylic paint layer for protection since gesso is porous? Or is just 2-3 coats of gesso on the back enough? Cheers, Andy

    • Nancy Reyner

      Hi Andy,
      This is a great question! Once you seal the back with the GAC100 (I usually apply 2 coats so now the wood is sealed well) then it should be fine with or without the gesso. Yes, gesso is absorbent, however, any moisture that may get absorbed in this gesso layer, will not affect the wood which is sealed. So in summary, the back should have 2 coats of GAC100 and only needs gesso if you want it to look whiter. The front needs 2 coats of GAC100, then gesso to strengthen adhesion between the paint and the sealed wood. By the way, Golden has now released new information that acrylic gloss medium can be used instead of their GAC100 if you prefer. They will both work fine sealing the wood. GAC100 is thinner so it sinks into the wood nicely, without adding extra brush strokes, which I like. Gloss Mediums have gone through a thickening process to make them a bit thicker. This means you may have brush strokes visible. So if you like that then this product will work also.

  21. lynne

    Hi Nancy! Loved your video! I have a question about sealing wood panels after I painted a watercolor on it – I know, not supposed to do that, but I wanted it to have the wood grain and raw wood look to it, and I really like it. But now, how do I seal it? Should I just use a liquid gloss varnish (I will buy Golden when I run out of Liquitex–orange label)? I assume I should seal both sides? Thanks so much!

    • Nancy Reyner

      There is no issue painting watercolor on wood. I don’t believe I ever said anything like that. However, what you are talking about is transparency so that the wood grain shows through. Transparency can be obtained in a variety of ways – not just with watercolor. You can use acrylic paints with water in the same way you use watercolor. You may need to add more water to get the right transparency you are after. You can also mix acrylic paint with clear mediums and get the transparency that way too. Watercolor dries water soluble, so you are right to question how to seal it. If you brush apply a water soluble sealer over the watercolor the paint may smear. I suggest using a spray application such as Golden’s Archival Varnish gloss. By spraying over the watercolor you will not reactivate the watercolor and therefore it won’t smear or bleed. Do not spray your first spray coat too heavily or spray it while it is vertical or it may run and this may smear the watercolor. Once the varnish coat is dry you will not have to worry about anything smearing the paint. To seal raw wood (on the backs and sides) I recommend brush application because you can get a more substantial coat on it. However, you can spray those areas too.

  22. DC

    Hi Nancy – I am working on a project on panels of cherry we made that combines woodburning and painting with Acrylics. Do you recommend I seal the wood first before woodburning, or do that step first and then seal with GAC100 before painting?

    Thank you for such an informative post!

    • Nancy Reyner

      Hi DC, Sounds like a cool project you’ve got going. I think you could seal either way – before woodturning or after. The idea is that unsealed wood will warp over time due to absorption of moisture – especially UNEVEN absorption. This can happen quickly when you apply waterbased paint like acrylic on one side of the wood and not the other. That is why I recommend sealing every surface of the wood that is exposed – back, front, sides. As long as you seal the wood prior to applying acrylic paint on the face it should be fine. Wood burning will not warp the wood – I am assuming there is no water involved in this process? If so, then seal first.

    • DC

      Hi Nancy,
      Thanks for replying so quickly! No, there is no water involved in the wood burning. I’m not sure if the wood burning will work on top of the sealer, so I think I’ll try a test both ways to figure out what works best. I’ll definitely use a sealer before applying the acrylic paint.

      Thank you!

    • C Rosa

      I used a clear gesso (also found recommended – but didn’t try this time – clear acrylic medium) under the areas for the acrylic painting, left the wood bare for burnings, and plan to seal in entirety after completion. Personally I found the clear gesso to be far too textured for my detail level – even with sanding. I will try the acrylic medium next time. (I was using Artist grade cradled wood panel.)

    • Nancy Reyner

      Thank you for adding this comment about using woodburning. I totally agree with you that you do not want to heat up a sealed wood surface with extensive heat like you would with woodburning tools. And you have come up with the perfect solution – seal everywhere you can except for the areas to be burned. Then after burning into the wood, and once it has cooled you can seal it properly. I want to make sure you are clear, though about the difference between gesso and an acrylic sealer. Gesso is meant for adhesion. This means it will be highly pigmented (the good quality ones not craft quality) to help adhere paint. It is NOT a sealer In fact it does the OPPOSITE of what a sealer does. This is a common misconception so I’m glad brought it up. You discovered that the clear gesso was too textured. YES! It is! It’s “textured” because of the high load of pigment particles meant especially to create an ABSORBENT surface that will help adhesion. Gesso’s – even clear ones – are usually matte and not glossy. An acrylic gloss medium will seal, but not a gesso. So next time, use something glossy like an acrylic gloss medium to seal your wood ALL OVER, EXCEPT to leave the area bare where you will burn. Once finished burning then use the same gloss medium to seal over the burn area. THEN apply gesso to the front face of your surface (You can opt to gesso all over to make the backs and sides look clean and white) but now you have an archival surface that won’t warp and will strongly adhere paint to its surface.

    • C Rosa

      I also am combining woodburning and acrylic painting. I am not sure about the idea of sealing prior to wood burning since you will then be burning sealer along with the wood; I understand that you are recommending a “non-toxic” sealer but it is only guaranteed non-toxic with regular application… this may not include any offgassing/fumes that occur upon burning. Analogous idea: Plastic cups are generally non-toxic for cold drinks, but not for hot, and definitely not advisable to breath the fumes when burning (as in don’t throw your plastic cups into the campfire but dispose of them properly). Also as a side note – if the sealer gets burned off then those areas of woodburning would then be unsealed… requiring additional sealing after completion.

  23. Sarah

    Hi Nancy, This is maybe a little off topic but you seem like you know a lot about gesso and priming etc. I have been attaching yupo paper to a cradled birch wood panel using a gel medium and then sealing the. yupo painting with resin. I have seen others first prime with gesso (GAC100) but when I went to the art store, they said that wasn’t necessary, the gel medium is enough. So far it seems fine but I have no idea what the benefits would be to use gesso in that situation. Do you? What is the best way to do this?

    • Nancy Reyner

      Hi Sarah,
      If the birch wood panel you are using is raw or unsealed, then I highly recommend sealing it first before applying the gel medium to adhere your yupo paper. The post explains why this is necessary, primarily to keep the wood from warping due to the wood absorbing moisture unevenly. Gel mediums contain moisture, so when you apply it onto one side of a raw unsealed surface this will cause an imbalance in moisture absorption. The post here describes two separate but equally important steps. The first is to SEAL. This is ONLY accomplished using a glossy medium such as the GAC100 or an acrylic Gloss Medium. Gessos are PRIMERS not SEALERS. Gesso is a highly absorbent product and will not seal, but will add adhesion strength to subsequent layers. In summary, each step has its own function. Seal to keep moisture control and protect the wood (glossy acrylic medium). Prime (Acrylic gesso) to add adhesion strength – so your painting won’t delaminate later at this layer, and use gel to glue. So as my post explains, the best procedure is to first seal with a gloss acrylic, then prime, then do whatever you are planning to do – paint or in your case apply a gel as a glue. Hope this helps.

  24. Roger Marsh

    Hi Nancy…
    This is a very nice and informative article. I have always worked with oil based lettering enamel paint over a period of years as a sign painter.
    I am now painting fine art paintings with artist acrylics on canvas in my retirement years. I have been reading all the posts about how to prep a wooden panel, which is different than what I’m used to. Working with oil based sign paint enamel is totally different than acrylic artist paints. I do know you’re never suppose to use acrylic over enamels, so is there anything at local stores like Lowes that can be used before applying gesso to the wood panels without strong chemicals that gesso would adhere to? I would like to start using luan so I can cut my own sizes to suit myself, but I want to be sure to use the right sealer that the water based gesso will adhere to.

    • Nancy Reyner

      Hi Roger,
      I recommend following the instructions I recommend in this blog article. I understand you want to use acrylic on a wood panel but don’t understand why you feel it necessary to use strong chemicals. In my article I recommend applying a water-based (so it is non-toxic) sealer such as Golden’s GAC100 or any acrylic gloss medium to the raw wood on all exposed areas. Once it dries, you would lightly sand the raised grain, then apply another coat. This should be adequate to then apply your gesso (also non-toxic) and then your paint (oil, enamel, acrylic, etc). I often use Luan for my wood supports and use these same procedures. Water-based gesso will adhere to any other water-based product, and will also adhere to raw wood, raw paper, raw fabric like canvas and linen, etc.

  25. Steve Cavallo

    I want to paint oils on natural wood. A friend cut slabs of wood from trees and I would like to do portraits and partial landscapes on them, leaving some of the natural wood grain exposed. The first pieces I prepared I coated both sides of the wood with linseed oil, then when dry I used Kilz Klear primer…. this was just a guess at how to prepare the wood. Any suggestions?

    • Nancy Reyner

      Hi Steve,
      That sounds like a good process, however I would check with a professional carpenter about this. Different types of wood have different characteristics. It would be good to find out how long the wood should dry before adding the linseed oil, or any other tips a professional wood worker would know.

  26. Ameya

    Hi! If I want to paint on laminate sheet which is attached on a particle board with acrylic medium then what care should I take?

    • Nancy Reyner

      Hi Ameya, you did not provide enough information for me to assist you. There are multiple types of laminate sheets, a variety of acrylic mediums, and a variety of paint types you may be using. I am sorry I cannot offer any advice based on the broad range of possibilities.

  27. Allan

    Hello Nancy my painting on a wood panel is completed no do I add varnish or anything over it to protect it?

    • Nancy Reyner

      Hi Allan, Yes I would recommend you apply varnish to protect your painting. As my article suggests, raw wood needs to be sealed in all exposed areas (back, sides as well as front) to keep the wood from warping due to any uneven absorption of moisture that can happen when unsealed. Now that the wood is sealed, and you have applied paint to the front surface (or other areas) you can apply an archival painting varnish over the painted area to keep the colors from fading, to allow for cleaning purposes, and to select a final sheen (gloss, matte or satin). There are many resources available online to find out more about archival painting varnishes. I like to use Golden’s Polymer Varnish Gloss because it is non-toxic. If my surface is highly textured I will opt to use Golden’s Archival Varnish Gloss in a spray can. Applying varnish in a spray is best for high relief texture to you don’t get puddling in texture crevices as you would with brush application.

  28. Radhika

    Hi Nancy, this article is very well written, thankfull for this detailed info!!
    So as its mentioned in the article, if i wish to work with Acrylics on wood, & wish to keep the natural wood look intact, then sealing the all of wood surfaces with 2 coats of Golden GAC100, then painting with desired Acrylic paints with Acrylic Varnish as finishing layer should be fine enough???
    Dear pls guide if this would suffice??

    • Nancy Reyner

      Hi Radhika,
      Yes that is correct. You would only be skipping the step to prime using gesso, because the gesso is opaque and therefore you would no longer be able to see the wood. Since you are skipping the priming step, just make sure your first coat of acrylic paint onto the sealed wood is a thin layer. It doesn’t have to be diluted with water to be thin, but should not be too heavily textured, to make sure your adhesion between your first layer of paint and the sealed wood is good.

  29. Minoo

    Hi Nancy, thanks for the detailed post! I was not aware that I need to seal panels before gesso so thanks for that. I’ve just sealed a panel (cradled Tung wood) with GAC100. I did two coats with a light sanding between coats. It has been a couple days and the panel feels a bit sticky still. Is that normal? Should I sand it again after the final layer (before gesso)? Thank you!

    • Nancy Reyner

      Hi Minoo, Your surface shouldn’t be sticky, unless you (1) applied the GAC100 too thickly or (2) you live in a hot humid climate, both reasons mean it will take longer for acrylic to dry. You only need to sand the GAC100 when you apply the first layer over raw wood, because the grain of the wood will lift, so you would not need to sand subsequent layers of medium. If you apply the medium thinly enough (not by diluting it with water, but instead by using a brush that is thinner at the bristle tips and applying small amounts to allow spreading it out thinly before it starts to dry)the first layer should sink into the wood fairly quickly, resulting in a non-shiny surface. Your second coat of the GAC100 also thinly applied will result in a satin surface. If your surface is super shiny then you applied it too thickly. Just wait for it to dry and make sure you have moving air (fan or open window) to help it to dry, and also temperatures that do not go below 56 degrees Fahrenheit. If it is too cold your layer may not cure properly – another reason to be sticky.

  30. Celia Britt

    Hello, Nancy, I, too am an aspiring artist. I have applied Onyx gel medium as a first and so far only layer to seal the surface of the wood panel. After I had done this a gal mentioned she had sealed her wood panel with one layer of GAC 100 and still the colour bled through.

    My questions are: Can I now use GAC 100 over the existing layer of Onyx, and would the Onyx have soaked into the wood as the GAC 100 does as you mentioned in your instructions? Thanks so much for your help.

    • Nancy Reyner

      Hi Celia, I am sorry to say that I have not used, and am not familiar with, Onyx gel medium. Therefore I cannot offer any advice, however here is my thoughts on it. If the gel medium was thin enough to penetrate into the depths of your wood panel, resulting in a matte surface, then that is good. You would then want to lightly sand if the wood grain is raised from that application of medium. Then you would apply a second coat so the resulting finish is more of a satin finish, not too glossy and not matte. This will explain why someone mentioned to you that one layer of the GAC100 will not adequately seal the wood from being still absorbent, and therefore allowing paint to sink into the wood. I do not know how the GAC100 will react to the Onyx. However, the tech department at Golden are very helpful, and I’m sure they could tell you about that. Hope this helps!

  31. Toni Marie Gomes

    Hi Nancy! I am new to acrylic painting. I have several birch underlay panels I am planning to work on. I was told by an artist friend to use polyurethane to seal them, then sand the polyurethane smooth, then paint. I should also note that I trace the outline of my drawings onto the panel to paint in my own lines so to speak. I purchased a thick polyurethane and put a coat on the panels already. What should the next step be? I do not want to use gesso and I do not want a white panel. Should I just fine sand the poly then paint then seal? Thanks ever so much!

    • Nancy Reyner

      Hi Toni, I have not used polyurethane as a wood sealer, but I imagine it should be fine. Make sure to seal all exposed wood areas (so that includes the back and sides). The idea is to seal the wood so that moisture won’t get into the wood causing warping. I usually do not use commercial products like polyurethane (there are many types so not sure which you are using) because these are products that are not meant to last like high quality archival fine art products. This means it may yellow or not bond as well to any acrylic paint you apply over it. The Polyurethane should soak in well to the birch, so you probably won’t have any issues with adhesion there. Polyurethane comes water based and also solvent based. If you used water based, then you can apply acrylic paint over it, and it should adhere well. If you used the solvent based, then it may not bond well to the acrylic, and you may want to sand it and apply a thin but super strong clear acrylic made for extra adhesion strength – like Golden’s GAC 200. Hope this helps.

  32. Bree

    Hi Nancy, I want to paint my art work onto wood panels but I want to keep the wood grains instead of covering the wood with white primer. Is GAC100 still a good choice to use? My medium is arcylic paint and black ink.
    Another silly thought is, can I just paint on the wood without any treatment and then seal it after my art is complete?
    Thank you.

    • Nancy Reyner

      Yes you can paint directly onto the unsealed wood, and you can also decide to seal the wood with GAC100 and then apply paint over that. Either way is fine, however, unsealed wood will absorb moisture, while sealed wood will not. This means that if you paint acrylic and ink onto the unsealed wood, it will soak into the wood very fast. You may have to apply a second coat of paint to get the color you want. Painting on unsealed wood also means you risk having the wood warp. If moisture from your paint goes into the wood from the top surface, the bottom will have a different amount of moisture coming into the wood then the top. This is how wood warps. If you are only applying a small amount of paint, and will be sealing it at the end within a short period of time after painting, then you can get away with painting on the unsealed wood, without it warping.

  33. Diana

    Hello, I am very new to this and am an aspiring artist and am so thankful to have found this post. I have number of raw wood panels sized 13.5” x 21” at my disposal and would like to use them for some paintings and mixed media pieces I have in mind. What type of brush should I use for sealing and what brush for priming? This is one of my very first attempts at any of this. Thanks for your help.

  34. Josh

    I’ve prepared 1/4″ birch panels with shillac and have been considering mounting raw canvas to them with archival PVA, but do I need to size the raw canvas prior to gluing and priming? I’ve stretched canvas before, and sized them with the gac100/400 combo, so I didn’t feel comfortable just gluing raw canvas to the board and throwing gesso (fake acrylic gesso) on it. After glued, do I need to seal the canvas prior to gesso or priming? I’d like to know that they are 100% as archival as I can get for DYI, even if my 5 year old is painting on them (with something other than oil paints). Thanks.

    • Nancy Reyner

      Hi Josh,
      I do not recommend using shellac on panels. I would glue the raw canvas, unsized, to the panel. After the glue has dried, I recommend stain sealing the canvas with GAC100. If you skip this step you may get some staining coming through from the canvas into your paints creating a slight yellowing to colors. After the stain sealing with the GAC100, then apply one or more coats of a good quality gesso.

    • Tom

      You mention not recommending using shellac on wood panels, yet a popular artist has a “Wood Panel Prepping” video on Youtube where he seals his wood panel with shellac before applying 3 coats of gesso. The shellac product does mention on its instructions that their product is also a protective sealer for arts and crafts. What’s the verdict?

    • Nancy Reyner

      Hi Tom,
      Thank you for bringing up the idea of using shellac on wood as a sealer. I have been in touch several times with Golden’s tech department about this topic. First let me say that there are many artists that use commercial products, (as opposed to fine art products) such as shellac, without caring about longevity – without caring whether the product will hold up without changing in appearance over time. Archival testing requires different levels for fine art as it does for “arts and crafts”. Shellac seems to be fine to use for crafts, but I still do not recommend its use with fine art.

      I sell my paintings through reputable art galleries, and therefore do not wish for anyone who purchases my work, to have to contact me down the line with any issues, such as yellowing, flaking of paint, or peeling off of layers. That is why I choose to only use products that are tested for fine art use, and only recommend these products for teaching and offering advice to other artists.

      I suggest you read these two articles (links below) written by Golden’s Tech consultant Sarah Sands, and decide for yourself whether to use shellac to seal your wood. It really does depend on what you are doing with subsequent layers after sealing and priming, and also whether you care about longevity.

      From my discussions with Golden, here is a quick summary regarding shellac (but please in addition, read the articles from the links above).

      1. Yes it is okay, but not recommended, to use shellac under acrylics (except for the slow drying OPEN line of Golden acrylics). If you decide to use shellac, Golden recommends using a pigmented white shellac like BIN as it is more effective and a better primer for subsequent paint then clear ones.

      2. Acrylic paints and acrylic products like Gesso can be applied over shellac, but shellac yellows and has embrittlement issues. Golden recommends using their Archival Varnish spray or MSA Varnish, which is far better for longevity.

      3. Shellac will adhere to acrylic, so you can apply it OVER acrylic paint layers, but is not recommended as a final varnish, as it will yellow and get brittle in time and removal of it would harm the acrylic underneath.

      I know it is difficult to get good answers, because there is so much information on the web these days, and not all of it accurate, and not all of it appropriate for what we are creating. I do try to research all my information as best as possible, and tend to err on the side of safe use. Hope this helps answer your question.


  35. Kim Kline

    Dear Nancy,
    I’m so appreciative of your tutorial here. My question is how to finish the sides of these wood panels. I will be prepping the top as you have instructed and applying resin to the finished top surface of the piece (I will tape off the sides to prevent the resin from coating the sides). How, then, should I finish the sides? I like the natural look of the wood so would not cover it with paint. Do I stain and seal or use a particular medium to achieve a clean, protected, natural-looking finish? What finish would compliment the resin top? Any recommendations as to what products might work best here?
    Thanks so much!

    • Nancy Reyner

      Hi Kim, I seal and prime all exposed wood areas (front, but also sides, and back) BEFORE I even start my painting. Once my painting is started I don’t want to risk damage to the face by turning it over to work on the back and sides. If you are using resin on the top I HIGHLY RECOMMEND you do whatever you need to for finishing the back and sides before applying the resin. Since you like the natural wood appearance, just seal it with the clear sealer I recommend (Golden’s GAC100), then don’t prime the sides with gesso. The sealer will slightly darken the wood (any liquid will do that with wood) and may give you the look you want. You can always experiment on a scrap panel to test whether the GAC100 will offer enough darkening of the wood. If not, then you can apply a tinted stain obtainable from any hardware store made for wood staining. You will still need to apply a clear gloss sealer over the staining to make sure the wood will not absorb moisture. Another reason you want to seal all over before applying thick layers of resin or paint, is that sealing the wood keeps it from warping BECAUSE the wood won’t absorb humidity unevenly. If you work on the face, while the wood is still raw on sides and back, you risk warping your panel.

  36. Carmel

    Hi thanks for all this information. I’m new to acrylic pouring and plan to use MDF panels as a cheap alternative to canvas (at least during the learning curve). Can I use Liquitex pouring medium as a sealer?

  37. Carmel

    Hi and thank you for all this information. I am new to acrylic pouring and plan to use MDF panels due to it being much cheaper than canvas ( at least during the learning curve). Can i seal it with Liquitex pouring medium painted on with a brush?

    • Nancy Reyner

      I would not. Each medium is specially formulated to work for different purposes. I would not brush apply a pouring medium, OR use it in place of a proper sealer. You need a thin formulation, and pouring mediums are a thicker pouring consistency. I recommend either Golden’s GAC100 brush applied, or any good quality gloss medium (just not one meant for pouring, or one thickened into a gel)

    • Carmel

      Dear Nancy
      Thanks for your reply. I live in Sri Lanka and don’t have access to Golden products- even acrylic gloss medium is not easy to come by. What do you think about using an acrylic waterproofing kind of paint that us used for exteriors and interiors? I have researched the market here and such a product is available. It’s a white liquid ready to use.
      Thanks again

    • Nancy Reyner

      That might work, although commercial products are not tested for long term archival use. In other words, noon-fine art products may sometimes flake, yellow or crack over time. It would be good to see if there is some way you can get any fine art quality acrylic medium. If you do use the waterproofing product that is available, it will be difficult to tell what will happen to it over time.

  38. Kitterain Walker

    Hello this has the mosst helpful piece I’ve seen about acrylic sealants, and thankyou for recommending certain brands as it makes it much easier to purchase.
    My question is slightly off topic but I have a large hollow decopatch reindeer I was planning on painting and I was going to seal it first, paint and then varnish like how you do with your wood panels, do you reckon this will behave in a similar manner?
    And if the piece is hollow would I need to do anything to the insides as well?
    Sorry for the odd question but I’ve been puzzling over it for a while.

    • Nancy Reyner

      If the reindeer is made of wood that is raw, (unsealed) then you can follow the same instructions I gave for sealing the wood panels. If it is possible to seal the inside then go ahead. If not, just skip it. It’s always best to have all unsealed wood sealed, but sometimes it just isn’t possible to get to all the areas. Seal what you can and that will help keep it from warping.

  39. Angie Janak

    Hi, I just did a painting that I really love on 1/4 birch plywood. However, I did not prepare the surfaces in any way, no sealer, no gesso. The plywood has a slight warp, but with the frame I made, it is not very noticeable. I’m concerned about future warping. Is there anything I can do now that I’ve already painted? Would sealing the back and sides help or cause more harm at this point? Thank you.

    • Nancy Reyner

      If you go ahead and seal whatever wood is still exposed on the back and sides it will keep it from warping any more. Your front is painted, so that will keep the wood from absorbing moisture there, the frame is helping to shield the wood that it covers, so any wood that is still raw and exposed still has a chance of warping.

    • Angie Janak

      Thank you! I’ll try that.

  40. Bianca

    Thank you for this article! I was wondering for a cradled wood panel, do I need to also seal and prime the back? That would mean working around the wood that is cradling it as there are bars that go across the back, like a grid, not just around the edges. I think this is because it is a 36×48” panel and needs more support. I worry if I seal and prime only the accessible areas of the back of the panel and not the parts under the wood supports, it will warp. Any thoughts? Thanks again!

    • Nancy Reyner

      Hi Bianca,

      That’s a very good question!You would only need to seal all the exposed wood areas. The wood that is underneath your crossbars as support is, as you said, difficult to get to, but this small of an area will not matter especially because it is probably touching the back of the main face of the wood. By the way, you only need one crossbar for every 42″ length. So you should only need one 36″ crossbar along the 48″ stretch of wood. The panels that my carpenter makes (which are sold commercially here do not need any crossbars because the special wood product used does not warp.

  41. JB

    I just would like to stay this is a great article! I used your steps to seal my wood panel and it turned out great! Thanks Nancy 🙂

    • Nancy Reyner

      Thank you for the comment! I’m glad the instructions worked for you!

  42. Peggy Baker

    Dear Nancy,
    Thank you for an informative article. I am wondering if you can answer a question? Years ago I took some faux painting classes in New York City. At that time, we primed with a product that also made the final finish feel cool to the touch like real stone.
    I thought it was gesso, but now cannot see to verify that fact. Can you tell me if it is gesso or if there is something else that I can use to create a cool feel? Thanks very much, Peggy

    • Nancy Reyner

      Hi Peggy,
      Gosh I have never heard of such a product. I do know that all acrylic feels cool to the touch when it is still in its curing stage, which takes up to two weeks. After that I was unaware that acrylic can remain cool. I recommend calling the tech department at Golden Artist Colors, Inc. They are very helpful and will know. If you find out please let me know.

  43. Aika Konn

    Hello Nancy

    I read this tutorial and thought this was awesome. I am painting on wooden panels right now and found this information valuable as I am not the most experienced with painting on wood. I wanted to ask you a question about preserving a wooden panel that was not properly sealed. One of the paintings I just finished was not sealed at all and I was wondering if there was anything I could do to help preserve the painting.

    • Nancy Reyner

      I would need more information to give you an accurate answer. For instance, is it oil or acrylic that is painted on the wood. When you say not properly sealed what does that mean exactly? Was it partially sealed? Once wood has paint on it you can apply a varnish over the painted face to help. And you can always apply the stain sealer and primer I mentioned on all exposed wood surfaces, like the sides and back. You are welcome to write again with more details.

  44. Anna

    Hi Nancy, can you tell me, if I want some of the natural wood to be left, unpainted in my background, can I apply the sealer only to the area that is to be painted? (working with acrylic on birch plywood if that is relevant) thank you in advance for your advice – and for this artcle!)

    • Nancy Reyner

      If the wood is raw then it should be sealed in all places. Otherwise humidity could affect the unsealed wood risking warping. Why not use a clear sealer all over on all exposed areas of wood, and then paint wherever you want to paint?

    • Chris Peacock

      I am intending the same – leaving some of the face of the wood unpainted. Where does that leave the question of priming – obviously I don’t want primer all over the wood. Should I prime only the places where I will be painting. Thanks in advance for your thoughts on this

    • Nancy Reyner

      I want to first make sure we are clear on the difference between sealing and priming, so my answer to your question makes sense. Sealing is necessary on ALL exposed areas of wood to keep it from warping. Sealers keep moisture from entering the wood unevenly and thereby warping it. A sealer is glossy, which indicates it will seal, and is therefore clear. Gesso or primers tend to be matte which means they are absorbent – doing the opposite of sealing. Primers are meant to enhance adhesion between paint and surface, contain pigment to do this, and are usually white. Sealers seal, primers encourage sticking power. Sealers are cleaar, primers are white. So ultimately you need to seal everywhere, but only need to prime the face where you plan to paint. If you want the wood to still show through on the face then seal all over including the face, then skip priming. You can always opt to skip priming, but should not skip sealing. Hope this makes sense.

    • Chris Peacock

      Yes, that’s fine – thank you for your time

  45. Tara Threatt

    So GAC100 is what you use to seal the panel?

    • Nancy Reyner

      Yes. You can also use a general acrylic gloss medium. The GAC100 is a very thin polymer, so it will not show brushstrokes and will sink into the canvas or wood surface. While the acrylic medium is thickened a bit, so it can show brushstrokes. I recommend using either one, but with NO water added to dilute.

  46. Rosine

    Hi, I will be painting on a cradled wood birch panel with acrylic paint for outdoor use in a humid climate (Bahamas). 1- do I follow your instructions for sealing a primer as above? (an artist friend recommended I seal with polyurethane, primer, paint and polyurethane over the paint to finish.)
    2- what do you recommend for weatherproofing?

    • Nancy Reyner

      Since your painting will be outdoors, I recommend using a commercial product instead of a fine art product. Fine art products are usually not meant for outdoors. I think your friend is correct using polyurethane. Just make sure you use a good quality polyurethane – one that won’t yellow or crack over time. You can also take your painting to an auto body shop. They have very strong clear finishing coats they use on cars which are outdoors all the time.

    • Roger Marsh

      I hope it’s ok to add a suggestion here. I was a sign painter for many years. I always used Ronan Stick Tite Primer and either Ronan Bulletin Colors or One Shot Lettering Enamels for a topcoat on plywood, mdo board or any kind of wood panel. Both paints are oil based and you have to buy them from a sign supply company that provides sign products to sign shops and the sign industry.
      I have used it on all types of wood panels and some of the signs I put out in the elements lasted anywhere from about 8 yrs. to up to between 15 and 20 yrs. here in WV depending where and how hard the weather hit them. I always sanded the wood with 100 grit sand paper then rolled on the primer with a sponge roller. This primer acts as a sealer and primer both on one coat. After the primer is applied then take your roller and run it clear across the panel one way all in one stroke overlapping each roll down the panel just a little to make sure the primer is spread evenly. You WILL get little bubbles in the paint but try not to overload the roller with paint, this will cause you to have fewer bubbles if you DO NOT overload the roller, but make sure the paint is absorbed deeply into the roller.
      Now, to get rid of the bubbles from the sponge roller, wait a few minutes, like maybe 5 minutes or so and run the roller clear down the panel one way again moving it over one lap of the width of the roller each time with the roller barely touching the panel on one stroke and roll it fast and it will burst the bubbles and level itself out. If it doesn’t get rid of the bubbles, you probably either have too much paint on your roller or you need to wait a little longer and lightly go over it again and again until they’re gone, or a quicker way would be to use a new dry roller to go over it barely touching the weight of the roller on it, always in one stroke, which I would recommend even though you would be wasting 2 rollers.
      Now to do the top coat, follow the same instructions as you did with the primer.
      If it’s a large panel use an orbital or vibrator sander with 100 grit sandpaper on the raw wood before the primer and also on the primer after it dries. Just remember this is for oil base outdoor sign paint NOT acrylic. You could check with the supplier, by now they might have an acrylic or water based sign paint because It’s been several yrs. since I retired. The cons of sign paint is the strong odor from the solvents so use them in a well ventilated area and follow the instructions on the can. The pros of sign paints are the high gloss finish and the smooth even finish that looks like porcelain when it dries. I hope this helps, I tried to be as thorough as I could.
      I am now doing fine art with acrylic on canvas and wanting to do some on wood panels in my retirement years. I was reading all these posts to see what sealer to use under the gesso so I’m in a new learning curve too with acrylics and board preparation for them.

    • Nancy Reyner

      Thank you for your thorough instruction! There is a big difference in process and products between a fine art product meant to be kept indoors, and a painted sign that will remain outdoors. For fine art products there is no need to go to such lengths (in my opinion) and use toxic products. As I mentioned in the article, I recommend using Golden’s GAC100 which is a thin water-based non-toxic sealer, meant specifically for stain-sealing so that water soluble impurities do not seep from the substrate into paint layers. It will also seal wood adequately from absorbing moisture, so it will not warp.

  47. Linda McElvey

    In one of your videos…or books…you said Kilz woukd work as a sealer. At least I wrotr that down. Now i see…many panels layer…that it is an oil based product. Think all my paintings will self distruct? Thanks for any clarification.

    • Nancy Reyner

      Hi Linda, I always use fine art materials and products if I can. I mentioned Kilz as a commercial alternative, and I do think it will work fine on rigid painting surfaces such as panels or wood (after all, it is made for walls not canvas). Kilz comes in both oil-based as well as water-based. If you are using oil paints it would be fine to use either type. If you are using acrylic paints, then it would be best to use the water-based. If you are concerned that acrylic paint will delaminate at the point where it is applied over the oil-based Kilz you may want to call the technical department for the company that makes Kilz and ask them. If you used a fairly thin layer of acrylic as the first layer over the oil-based Kilz and the Kilz was somewhat absorbent (not glossy) then there will probably be good adhesion between the two, with no delamination issues. What is important to understand is that there are many factors that determine adhesion strength between layers, as well as several processes you can do to increase the adhesion (ie. a light sanding of the underlayer before applying the over-layer.) Hope this helps.

    • Carol

      Hello! I want to use an Ampersand Panel for pouring an Acrylic painting. It will be a wedding gift. The panel was caught in a small flood in our basement and went unnoticed. Now it has some black mildew on the face and supports. What would you suggest is the best method, for removing and covering the spot so it will be useable? Also, the edges are raw wood. I want to use the edges so the painting doesn’t require a frame. I was planning to use Kilz after wiping with bleach then recovering with Gesso. Now, I’m not sure. Can you apply with a foam roller?

    • Nancy Reyner

      HI Carol,
      I wouldn’t want to mess around with black mold. I would throw it out and purchase a new one. However, to remove the mold try researching how black mold is removed in regular households, usually on walls. Most likely there are chemicals to deal with this, but are probably toxic, which is why I would throw it out. Regarding the panel prep, whether you remove the mold or purchase a new panel, you would need to seal all exposed areas of the wood. You can use Kilz as you had suggested or GAC100 from Golden, or any Gloss Medium, applying any of these in two coats, then applying the Gesso. I don’t use a foam roller for any of these preparation coats, as I don’t want any bubbling. However, you can try using a roller and make sure it can apply the product smoothly without bubbling once dried.

    • Greg Westfall

      I have used Kill MAX (water based) many times with acrylics and it works well. It is definitely a different surface than gesso. It feels kind of like porcelain. But no adhesion issues.

    • Nancy Reyner

      Hi Greg,
      Thank you for adding your experience with sealers. Yes Kilz does work but only for rigid surfaces. It does not have the flexibility built into the product for use on canvas or linen on stretcher bars. Kilz is NOT a primer. It is a sealer. It creates a barrier between the substrate and the primer to trap impurities that cause staining. This does get confusing, and I try in my article to distinguish between sealers and primers. So Kilz is a substitute on rigid surfaces for the stain sealer or stain barrier, but will not add adhesion strength and therefore is not a substitute for a primer. Using a primer such as Gesso will enhance adhesion between the substrate and paint layers. You need BOTH! A sealer and a primer.

    • Susan

      Thanks so much for all this helpful info! Lately I’ve been using flat birch panels which I coated with white gesso before starting to paint on them. Will there likely be a problem since I didn’t first coat them with a sealer, and also because I didn’t coat them with anything on the backs of the panels?

    • Nancy Reyner

      HI Susan, if you did not seal the face of the panel, under the white gesso, you can still apply the sealer now OVER the white gesso, then apply the gesso again over the sealer layer. The sealer will absorb any of the water soluble impurities that move up into its layer, turning IT slightly yellow, but won’t let the impurities move up into further layers applied on top of it. You would want to apply the gesso, then, over the sealer to hide that layer and give you a nice white starting point again. You can always seal the back of the panel, at any time, if it is still raw even after the painting is finished, to keep it from future warping. If the painting is already in process or complete, and you are worried about problems because you have not applied a sealer to the face of the panel, under the gesso, then all will be fine IF you do not see yellowing at this point AND IF you do not plan to apply more layers that are thick. In other words, any yellowing due to impurities that moves upwards from substrate to upper layers, shows right away, within the first day at least, and will continue to move upwards only as thicker layers are applied, such as several coats of varnish, or heavy applications of gel.

  48. crissea grovenor

    Fantastic information thank you so much.


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About Nancy

Nancy Reyner paints exotic versions of heaven, using gold leaf and other unusual materials. A contemporary abstract painter, she feels art is a rewarding pursuit that adds quality of life. Nancy shares this passion with her students & offers classes, articles, books & videos, encouraging the courageous use of materials and artistic expression.

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