In the days before canvas, wood was the main vessel on which to paint. Present day artists have found that wood offers a different vibe, and many are using wood instead of canvas not only for conventional paintings but for whatever type of art they want to make.
Prime Your Wood
Wood is a porous medium. When using wood as a canvas, whether new wood or reclaimed, many artists want to fill the pores in the wood. This fills in the inconsistencies and makes it smooth. If the wood is not primed, the paint could be absorbed into the surface of the wood. You will use more paint and the vibrancy of the paint will be lost, the outcome being more of a dull look. Your paint might not stick at all to unprimed wood if it is dirty. Priming the wood will allow the colors to pop, giving the piece more distinct look. One type of primer is gesso. Some oil based primers will hide stains on the wood. If you want a more natural look, you might use clear shellac, a color close to that of the wood or none at all.
Lay It On Thick
Compared to traditional canvas, wood as a medium can offer more character in the piece. Oil often exhibits a thick, heavy structure to a painting. By layering your oil paint coat after coat, it can fill in gaps in the wood left without primer. The early coats of the paint will act as primer. The wood emits a persona of its own with the layers and shadowing that oil paint displays. These techniques are useful particularly for floral painting. The petals and leaves can appear more alive without the constraints of a totally flat backing.
To Seal or Not to Seal
Sealing your work can affect its final look. Most oil-based seals will add a gloss to your painting. The particular type of look you’re going for can be affected by that final step. Sealant comes in spray form as well as to paint on. A dramatic painting might not have the same appeal if it shines from the sealant layered over your work. A more joyful or youthful painting might be enhanced by a shiny coat. A coat of sealant is generally recommended to protect your artwork. With art being so subjective, though, you as the artist will need to decide which methods will produce the overall feel you want to accomplish. In art, as in life, there are few hard and fast rules. You, the artist, are in charge. As you broaden your horizons by painting with oils on wood, you will decide which techniques work best in your art.