Wood is a good surface to paint on. It is rigid, it lasts longer than stretched fabric, and it takes texture in a way canvas cannot. It is also the surface most likely to ruin a painting weeks after you finish it, because wood is full of soluble compounds that will travel up into your paint if you do not seal them in first.
That one step is what separates a wood panel that still looks right in ten years from one that has gone amber in the pale areas. This guide covers preparing the surface, sealing it, painting it and finishing it.
Why paint on wood at all
Canvas flexes. Every time it is knocked, leaned against something or moved between temperatures, the fabric moves and the paint film on top of it has to move with it. A rigid panel does not do that, which is why wood is generally considered the more archival of the two supports.
It also holds heavy texture without the surface bouncing, and it lets you sand back between layers to get a genuinely smooth ground, which is difficult on weave.
This is not a niche choice. Jackson Pollock worked on Masonite, fiberboard, glass and tin as well as canvas during his drip period, and a great deal of historical painting is on panel rather than fabric.
What you actually need
Short list, and most of it you may already own:
- The panel itself, untempered hardboard or birch plywood
- Sandpaper in two grades, around 120 to 150 and around 220
- A tack cloth or any lint-free rag
- Acrylic gloss medium, for sealing
- Acrylic gesso, for priming
- Your paint, and a brush, roller or spray depending on the finish you want
- A final varnish
You do not need a separate wood primer, a putty knife or a shop vacuum for an art panel. Those belong to furniture work, which is a different job with different requirements.
Preparing the wood
Clean it
Wipe the panel down and let it dry completely. If it has been in a garage or a shed, wipe it again — a film of dust you cannot see will stop the sealer keying properly.
Sand it
On a raw panel, start at around 120 to 150 grit and work with the grain rather than across it. You are knocking back the fuzz and any raised fibers, not reshaping anything, so there is no reason to reach for very coarse paper. Anything down at 40 or 60 grit will gouge a hardboard panel and you will see those scratches through the finished paint.
Between coats of sealer and primer, drop to around 220 and go very lightly. Two or three passes is enough. Wipe the dust off before the next coat.
Seal it, which is the step most people skip
Wood contains water-soluble impurities. As acrylic dries it draws water down into the support and then back up again, and it carries those impurities up into the paint film with it. They stay there. The effect is called Support Induced Discoloration, and it shows up as an amber or yellow cast in your lightest passages, sometimes weeks later.
It is specific to acrylics — the mechanism depends on how an acrylic film dries — and it is entirely preventable. Golden, who did much of the research on it, now recommend sealing bare wood with two or more coats of acrylic gloss medium applied directly to the support, in preference to their own GAC 100. Preparing other surfaces follows the same logic with different sealers.
Let each coat dry properly, sand lightly at 220 between them, and only then move on to primer. Gesso alone will not stop it. Gesso is porous, and the discoloration travels straight through.
Prime it
Two or three thin coats of acrylic gesso over the sealed panel, each sanded lightly once dry. Thin coats sanded flat beat one thick coat every time, and you can build a surface as smooth as you have patience for. If you have not worked with it before, we cover what gesso actually does in more detail.
Applying the paint
With a brush
Use a brush wide enough to cross the area in one pass. Load it moderately — an overloaded brush leaves ridges at the start of the stroke and runs dry at the end — and work in one direction, edge to edge, with light pressure.
Two thin coats beat one thick one. A thick coat on wood sits on the surface, dries at different rates across its thickness, and is far more likely to show brush marks when it cures.
With a roller
A small foam or short-nap roller gives you a flatter, more even field than a brush, which is useful for backgrounds and for large single-color areas. New rollers shed, so press a strip of tape over the nap and pull it off before you start — that takes the loose fibers with it.
Keep the pressure light and do not try to squeeze the last of the paint out of a roller that has gone dry. Reload it instead. A dry roller dragged across the surface is what leaves tracking marks.
With spray
Spray gives the most even finish of the three and removes brush and roller marks entirely, at the cost of needing space and ventilation. Work outdoors or in a well-ventilated room, in thin passes, keeping the can or gun moving.
Avoid direct sun, a fan blowing across the piece, or anywhere near a vent. All three dry the surface faster than the coat underneath, and you get a skin that wrinkles.
Finishing the piece
Once the paint has fully cured, a final coat protects it. Three common options, and they are not interchangeable:
Acrylic varnish
The usual choice for acrylic painting. Available in matte, satin and gloss, and a removable varnish can be taken off and replaced decades later without disturbing the paint. This is what most people want.
Wax
Applied by hand, then buffed once it has hazed. It gives a soft, low sheen that suits furniture and decorative pieces more than paintings. Buff the excess off rather than leaving it — unbuffed wax stays soft and collects dust. Keep waxed pieces out of direct heat, which softens the finish.
Polyurethane
A hard, durable coating for furniture and anything that gets handled. Worth being precise here, because it is often confused with polyurea, which is a sprayed industrial elastomer used for truck beds and waterproofing and is not a wood finish. Polyurethane is strong-smelling, needs ventilation, and is effectively permanent — it cannot be removed cleanly later. Good for a painted tabletop, wrong for a painting.
Choosing a panel
The question that comes up most is what the difference is between hardboard and Masonite. There is not one. Masonite is a brand name for hardboard, from the process its inventor patented, and the name stuck as a general term for the material even though the brand no longer makes the panels.
The distinction that does matter is tempered versus untempered. Tempered hardboard was traditionally hardened by soaking it in tung or linseed oil, which leaves an oily residue and acidity that cause adhesion problems and can work through several layers of gesso over time. Buy untempered for painting. Some art-specific manufacturers now make tempered panels by a process that removes those compounds, but unless the packaging says so explicitly, untempered is the safe assumption.
Birch plywood is the other common choice and is a good one, though on anything much over about sixteen inches you will want a cradle on the back to stop it bowing.
If you would rather not do the preparation
All of the above is surface preparation, and none of it is painting. It is a couple of evenings of sanding and sealing before you make a mark. Some people enjoy that part; a lot of people find it is the reason the panel is still leaning against the wall six months later.
A paint by numbers kit comes at the problem from the other end. The canvas is already primed and ready, so you open the box and start painting. Ours arrive rolled in a tube rather than folded, which is the difference between a flat surface and one with a crease down the middle. You can see finished ones in our customer gallery, or browse the kits.
If you do want to paint on wood, seal it first. That is the part that matters, and it is the part almost everyone leaves out.
