Why Use Wood Panels for Painting?
There are many types of surfaces that painters can use for fine art painting. Canvas on stretchers 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 causing 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.
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 have two issues with commercially made wood panels. I like to work large and in sizes that are not standard. Since commercial panels only come in standard sizes, and only up to around 40″ per side, if you want a custom size, or something larger than 40″ there are not many options. Some commercial companies offer custom panels, but may take up to six months (not kidding) to get it to you. Commercial panels use hardboard for the painting surface. Hardboard can get very heavy when used for large sizes. I created my own brand of panel, Nancy Reyner Custom Artist Panels, only available through, Artisans Art Supply. These are high quality panels, custom made in three weeks or less to your size preference, cradled with 1 7/8″ sides, and made with a special poplar wood material that is super lightweight.
Preparing Your Wood Panel
Oil painters must seal wood to stop any acidic oil in the paint, from penetrating into the wood support, which can cause the fibers to rot. While acrylic painters do not have this same issue, sealing is still an important step if you plan to use acrylic paint, 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.
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 by creating a barrier. A primer is a foundation layer that improves 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 seal the wood unless multiple applications are used.
A general rule is to apply at least two coats of sealer directly onto the raw wood to protect the wood. Then apply primer to enhance adhesion, return tooth to the surface, and whiten the surface for optimizing paint colors you plan to apply over it.
Instructions to Prepare Your Panel
(1) Clean off any dust or debris from all faces of the panel including the cradled sides, 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.
Tip: Let one surface dry fully before flipping over to seal the reverse side. Drying times can vary. If dry to the touch with no tack, it can be flipped over without sticking to the 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. There is no need to heavily sand, just an easy swipe with the sandpaper will suffice. Sanding blocks with a fine to medium fine grit are convenient for this purpose.
(5) Wipe the surfaces clean after sanding, then apply a second coat of sealer. Usually two coats of a sealer is sufficient, making the wood appear slightly satin or glossy in sheen. Optionally add more coats if you desire a more saturated seal. It is important to allow sufficient drying time (1 to 3 days) before continuing to prime or paint, so that the size can coalesce into a uniform film (especially important for oil painters).
(6) When fully dry after sealing, it is recommended 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 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.
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 satisfactory when used with oil paint.
Once the gesso is dry to the touch it is ready for applications of acrylic paint. Wait 1 to 3 more days for applications of oil paint.
Here is a link for more information on Nancy Reyner Custom Artist Panels