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

by | Mar 14, 2017 | Blog | 140 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.
 

Additional Information

Order custom-size lightweight panels
GOLDEN’s article on preparing panels
Adhesion in Paints and Coatings

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– END –

 

140 Comments

  1. Amethyst

    Hi Nancy!

    Quick question: I bought a regular piece of smooth plywood stained it and applied a clear gesso and it isn’t drying clear. It kind of has a white dusty kind of look. I’ve tried multiple coats and sanding in between and I’m still getting the same thin white layer over the piece where you can also see some of the brush strokes. Is there a way to fix this?

    Reply
    • Nancy Reyner

      Hi Amethyst,
      I highly recommend against using any type of “clear gesso”. Gesso is a white pigmented product that enhances adhesion. The pigment is an important ingredient for this purpose. A clear gesso means it has no pigment in it. So it is misleading in its name. A clear gesso is actually a semi-gloss or matte acrylic medium. Acrylic is naturally glossy. This means that any matte or satin or semi-gloss acrylic product has a white powder in it to give it some tooth. If you use “clear gesso”, or matte or satin acrylic mediums, you will get a translucent white film over whatever you apply it to. I believe companies that sell this are misleading the customer by repackaging a matte medium as “clear gesso”.

      As I describe in this article, there are two different steps to take when working with wood, each used for a different purpose and each requiring different products. First you seal (with something glossy). This is important to keep the wood from warping. The second step is optional. That second step is to prime with gesso which adds adhesion strength to the next layer applied to it, and also adds a white coat. It sounds like you are trying to seal and prime using one product and one application.

      Next time, use a gloss acrylic medium to seal. Then skip the priming step with gesso, and paint directly onto the glossy coated wood. If you want to add some tooth, lightly sand the glossy surface. You will make it slightly matte doing this, but there is no white powder added to this process, and therefore if you applied gloss over it again, the matte effect will disappear.

      Unfortunately the only way to fix what you have now, is to sand off all the way back to the wood and start over. Remember anytime you use a matte or satin product (which includes clear gesso) you will get a non-removable white film.

      Hope this helps!

      Nancy

  2. Julia

    Hi Would you recommend using “Gamblin’s Gamvar or Golden’s MSA Varnish (for brush applying) or their Archival Varnish (spray application)” on a fine art piece from 1944. Its a relief painting/sculpture … it has a couple of linear cracks. I’d like to protect the colors and protection from insect damage.

    Reply
    • Nancy Reyner

      Dear Julia,
      Since the piece is from 1944, it probably uses oil paint. It is probably very dry at this point, if it hasn’t been restored since then, so adding a varnish would be a good idea for protection, avoiding any future cracking and reducing any color fading. Since it has relief texture, a spray varnish would be the best. Brush applications would work if the texture is slight. If the texture is raised quite a bit, then brush applying may create puddles in the crevices. Golden’s MSA Varnish comes in a spray (with a different name, though) called Archival Varnish. I recommend using only gloss, so the Archival Varnish Gloss will work very well. Matte varnishes contain a white powder that may not work well over the old painting. Another consideration is the back of the painting. Check it out to see if the canvas is OK. If not, you may want to apply an acrylic gloss medium over the canvas back to keep any moisture entering the painting through the back.
      Nancy

  3. Alex

    Hi Nancy

    Thank you so much for this detailed run-down! It is so helpful.

    I see you’ve got a lot of comments, I’d be here all day if I were to comb through each page – so apologies if my question has been asked before.
    I’m new to painting on wood panels and am very excited to go out and buy all the supplies I’ll need before I can get started.
    Forward thinking, is there a varnish or medium I should use or that you can recommend (specific to painting on wood panels) to finish & seal in my painting?

    Thanks and look forward to hearing back.

    Alex

    Reply
    • Alex

      Just to clarify, I’ll be painting on wood panels (birch) for fine art purposes that will be on display inside – not for furniture or outdoor use etc.

    • Nancy Reyner

      Hi Alex,
      I’m glad you are finding this article useful for your artwork. Once you prepare your panel following the instructions in this article, you can then paint on the wood. When you are finished painting you would need to apply a final topcoat of varnish. Fine art varnishes are different than hobby or commercial varnishes. Fine art varnishes have two important qualities. (1) They are REMOVABLE for cleaning purposes, and (2) they have UV protection so paint colors don’t fade. Golden has lots of great articles on their site. For starters here’s a good one: https://www.goldenpaints.com/technicalinfo/technicalinfo_varnapp

      You haven’t told me what type of paint you will be using, and this makes a difference in the varnish product you will choose. If you are painting with acrylic, then you will need to do two steps over your finished painting. You need to apply what’s called an “isolation coat”. For this I recommend 1:1 Golden’s Soft Gel Gloss with filtered water. Over this you can then apply your varnish. I recommend Golden’s Polymer Varnish, which comes in a variety of sheens – gloss, matte and satin. Varnishing is tricky and I do recommend reading the articles prior to purchasing anything.

      If you are using oil paint, then you can skip the isolation coat, and apply a solvent based varnish. I like Gamblin’s Gamvar or Golden’s MSA Varnish (for brush applying) or their Archival Varnish (spray application).

      Nancy

  4. Tom

    Hi Nancy,

    I went out and got Golden’s GAC100 Acrylic Primer and Extender and did exactly like you said in your wood preparation instructions. I often extend drying periods between steps because I’m overly cautious and in no hurry. 1st coat went fine. Dried well. Sanding, cleaning, and all the usual steps went fine. Second coat seemed to go fine. The only doubt I have right now is that after about 5 days, the surface does not seem “kitchen counter” or “glass surface” dry. There seems to be a slight tackiness or rubbery feel to it when I press slightly with my the palm of my hand, or handle the panel with my hands. It’s very subtle but it’s there. I applied rather thin, normal coats, nothing too thick. In my 30+ years, my surfaces have always been bone dry before applying the gesso. This one seems to have a slight tackiness about it. Like I said, it very subtle, but I can feel it. Could this be normal for GAC100? Could this be because of the actual nature of the GAC100 product. The Golden website indicates that the GAC100 is “Useful for thinning or ‘extending’ colors as well as increasing ‘flexibility’.” I’m both curious and rather concerned because I don’t want to apply my gesso on a sealed surface that does not seem to be bone dry. I know it’s probably going to be difficult for you to make an assessment without being able to touch the panel surface in person, but maybe you can give me an answer from afar.

    Thanks for your time,

    Tom.

    Reply
    • Nancy Reyner

      Hi Tom,
      That’s a very interesting question. I too have found the surface to be a bit tacky at times. It sounds like you did everything right, and after 5 days it should be bone dry as you said. In my experience I have found it varied in touch when dry. I do not think it is an issue that it has a slight tack, and applying gesso over it at this point should be fine. There are always variables with every process, so this means we will get variation in our results. Acrylic is so stable though that again I do not think it is an issue of concern. Acrylic will still continue to dry even if overpainted with other acrylic layers. The variables I found are: (1) Humidity and warm temperatures slow the drying and may keep the layer tacky for longer (2) The wood itself may have elements in it (either naturally occuring or in the processing of it) that react with the acrylic to keep it tacky longer (3) Different types of wood have different densities, and therefore some of the medium may sit on the top surface instead of sinking into the wood, causing the slight tackiness you feel (4) Make sure you mix the GAC100 well before applying. If it separates in the bottle and you only use the top part this could be an issue.

      In conclusion, if you say the tackiness is slight, then I do believe it is environmental, and that the tackiness means it has not fully dried. Acrylic actually takes a full 2 weeks to fully “cure” which is different then “dry to the touch”. Within this 2 week period it is fine to continue layering over acrylic layers. Once your painted wood is finished, before wrapping it or storing it, you want to wait a full 2 weeks for all the layers to fully “cure”. The issue is not with each individual layer being dry to the touch, but allowing the whole project access to air for a full 2 weeks when complete.

      Hope this helps!

      Best,
      Nancy

    • Tom

      Hi Nancy,

      Some of the points you mentioned crossed my mind when I was questioning the whole thing. First of all, the GAC100 came in 8 fl. oz containers and were easy to rotate in my hand for easy mixing so the possibility of the contents being separated in the container was virtually impossible after mixing. Second, I thought I may have applied too thick a second coat, but I know I applied as thin a coat as possible. I think the answer is environmental. Montreal has been going through combinations of heat waves, up and down periods of humidity, etc. exactly the same time that I applied the sealer on my birch panels. Yesterday and today, with the humidity and heat subsiding, the surface seems a little dryer and harder than before. I know that the nature of acrylics when applied over certain thicknesses can be a little tacky/rubbery as it dries, so I assumed the GAC100, which is acrylic based, could present these dilemmas. I’m encouraged by the results in the last two days and I think you hit it on the nail when you said it could be environmental. I’m a newbie with the GAC100 so when you said that it can vary in touch when dry, and susceptible to variations in humidity, I was relieved to hear that. Like I said in my previous post, I’m patient and never in a hurry, usually preparing panels months before actually applying my first brush stroke, so I’ll let it cure for a while and go from there. Thank you for enlightening me on the subject.

      All the best,

      Tom.

  5. Michelle Roberts

    Hello Nancy, I want to paint on large wooden slabs an oil painting of my kids homes and then seal it and turn it into an end table. How would I go about it from the preparing the wood and to the sealing of it at the end?

    Reply
    • Nancy Reyner

      Hi Michelle,
      Follow my instructions in this article for preparation of the wood. If you want to use it functionally as a table, I suggest your final top coat to be a commercial high grade product such as polyurethane. You want the top coat product to be durable, non-toxic once dry, and waterproof. Using a fine-art product for varnishing like I suggested would not work.

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About Nancy

Nancy Reyner is a professional fine-art painter with over 30 years experience using a variety of mediums including oil, acrylic, watercolor and mixed media. She has appeared on television for HGTV’s “That’s Clever,” and authored several best-selling painting books with F&W Media. She currently lives in Santa Fe, NM. Read more.
 
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