A Look At The Edge

I paint on wood. I prefer its rigidity and smooth surface to that of canvas. I use both store-bought and hand-made wood panels.

Wood was the very first material employed as a base for oil painting. In fact, the Mona Lisa is painted on a solid sheet of poplar. There’s roughly 500 years of information out there – if one searches – on the attributes of one surface over another. Today there are many more choices as well, available through art suppliers and lumber stores. Here are the basic four:

1) Masonite is cheap and has two surfaces so you can choose either smooth or rough, but it has a tendency to soak up thinner and oil very quickly. So if you’re working in thin layers or glazes, the first few layers will feel chalky and weird. Plus it’s really heavy and very susceptible to moisture, off-gassing, and general frailty over time.

2) MDF (medium density fiberboard) is similar to Masonite and is also one of the heavier materials one can work on — the main reason I haven’t even tried it.

3) Sizable flat solid wood panels of traditional manufacture (like the one the Mona Lisa is on) are expensive and difficult to come by.

4) Plywood is durable, strong, and available in a variety of constructions. After much exploration and many mistakes, this is the material I now use for my work.

Virtually all plywood of any significant size these days is “roll-cut” from the tree. That is, it’s shaved from the lumber against the grain, as the log is spun on a giant lathe. For this reason the individual plies are susceptible to warping and cracking. However, when laminated with their grains at right angles to each other, the wood becomes stronger than it would be in nature. The thicker the plies and the more there are of them in any given sheet, the stronger the sheet of plywood gets.

Standard construction plywood isn’t refined enough and is usually a soft wood, like pine. Marine plywood and pine also have more severe off-gassing properties, and the knots can bleed through and discolor the work. Maple is excellent but expensive. Oak is great too, but just as heavy as masonite or MDF. Therefore, birch (in my experience) fits the median standard extremely well.

Birch plywood in and of itself comes in quite a few forms. The best selection can be made by examining the edge. The above photo shows three 1/4″ cuts readily available in a home improvement store like Lowe’s or The Home Depot.

  • The one on the left is a low grade 3-ply birch, suitable at best for a temporary work or graphic pieces without much detail such as a protest sign.
  • The middle slice is a 1-ply core with a veneer front and back but who-knows-what-defects in between. I’m suspicious whether the core is even birch — note the porous grain. It’s cheap but not really suitable for painting, as the veneer is about 1/32″ thick and is likely to warp or crack within a year or two, especially in humid environments.
  • The one on the right is a 2-ply with the same type of veneer, a little less likely to warp overall but still susceptible to the same problems as the center piece.

All three could be used to stiffen a canvas used as a substrate for the actual image but not adhered to the plywood nor painted directly upon.

This brings us back to what’s available at the local art store …

Here we find a Blick Studio Birch Panel — the three tiny layers at the top are what we are concerned with here. It’s a higher grade of wood, I am sure (with no gaps or plugs), and it has an edge cradle to guard against warping. However, it’s of the same construction as our cheapest 1-ply at the home improvement store, and the entire surface sheet is half the thickness at only 1/8″!

Next we have a brand called Art Alternatives (again cradled). Five plies! Nice. But beware! Look closely and you’ll see that the top ply is a veneer that is thinner than a sheet of card stock (note the chipped corner).

It’s not that one shouldn’t use these panels at all, I just wouldn’t recommend painting directly on the top surface as it can split or warp. Also, if you happen to not like the work you’ve done and want to re-use the panel, a veneer is more likely to be sanded through before one gets rid of the offending image.

Below are some that will work better for applying paint to directly.

I found Elephant Board at the same store. It’s cradled and only three plies but they’re good thick plies and the top one, though well sanded down, was a ply and not a veneer.

Midwest Products produces a variety of fine plywoods uncradled, and they’re available in smaller sizes if you’re doing smaller work.

Finally, if you are going to make your own panels, I have had great experience with Baltic birch plywood. The Woodworkers Source has a very comprehensive blog article on this material, but basically one should try to find it without plugs or knots – and the thicker the better. I usually use 1/4″ or 1/2″. It’s available up to 5’x5′ and as thick as 3/4″.

Sometime soon I’ll post the process I use in preparing a panel.