I love oil painting on wood for a few reasons. One of the main ones being the smooth surface that it offers, and the pigment that it displays. I will highlight some of the differences in oil painting on wood vs oil painting on canvas:
Preparation before painting
When you are painting on canvas, there are two options. You are either buying the canvases from an art supply store, or you are making the canvas yourself. Regardless, for either, I recommend priming the canvas with some gesso. I also recommend wetting the back side of the canvas with some water to tighten up.
With painting on wood, if you are buying from the store, it is the same idea. It should already come ready to be painted on. I personally like to add at least one thin layer of gesso to ensure that the oil paint will not seep too far into the wood.
If you are painting on wood that you have cut recently, you are going to want to sand down the wood board. After this, I recommend also using gesso because of not only the seeping (which can be even worse on fresh unprimed wood) but also because some of the woods pigment can come out and yellow the paint you have laid down
Blending wet materials on wood vs canvas
One of my favorite parts about painting on wood is its absorbency outweighing that of canvas. When you are painting with a light wash on canvas, it is obviously very runny. On a canvas, it can drip down.
With wood, it often absorbs much quicker than it would on the canvas. This can be used to your advantage if you understand the properties of it (like most mediums in the art world). I think it makes it easier to have a thicker build for your oil paint.
The texture of the surface
Perhaps the best part about painting on wood is how durable it is. You do not have to worry about putting too much pressure on the surface and morph the shape of the canvas.
Likewise, it is incredibly smooth to paint on. A problem that I have reached as an artist when photographing for prints in particular is the texture of a canvas. With the ridges on full display, it can give negative affects to the painting I might not have wanted.
With wood, there is no unnecessary ridges. It is one solid surface. It makes the texture of the oil paint stand out even more!
