A Painting How to: Prime a Canvas with Gesso

In the realm of how to paint pictures, you can do things the easy way or the hard way.

What is "priming a canvas?" Quite simply, it's treating the surface so that you can paint on it with relative ease. This is what you do to prepare canvas for painting. Of course, many artists buy a canvas which has already been primed.

Priming has nothing to do with making your painting look more realistic. That only comes from the artist's skill. Priming only affects the texture of the painting surface and how easily it takes the paint you apply.

Imagine painting on a wool sweater. All of those fibers are knocking about, grabbing paint and redistributing it where you don't want it. The paint doesn't go on smoothly and there are gaps. If you want to do a wash to tint your background, an untreated (un-primed) surface isn't going to take the wash well. You'll end up with gaps. That may prove interesting and create fascinating textures, but usually that's not what we're after.

Personally, I like to paint. Preparing to paint is not painting. That's simple enough, but if you love the idea of doing it all yourself and living the earthy life of simplicity, this might help. Of course, you can go all the way and grow your own cotton, weave it into canvas, make all your own pigments and make your own paint brushes, too. Here, though, we'll talk about preparing raw canvas as a painting surface.

When I was green and didn't know much about painting, I tried oils on raw canvas and the result was, well... less than desirable. You see, canvas has some lovely texture, but raw canvas has fibers sticking every which way but loose. Painting on such a surface is a bit like laying on a bed of nails. Ouch! Paint doesn't adhere very well, and you have interference from all of the little fibers. Paint might not go where you want it to.

The painting I did on raw canvas was of the lunar excursion module sitting on the lunar surface with a full Earth above the horizon. My Dad loved it and promptly hung it in his office. You see, he worked for one of the NASA contractors in the 1960s. Lunar landscapes were all the craze.

With gesso, canvas can be made smoother and its surface made easier to paint.

First of all, you need the following materials:

• Gesso. I recommend Liquitex acrylic gesso.
• A broad paint brush (this can be an ordinary house painting brush; 3–4 inch is okay).
• A broad paint brush for dry work.
• A stretched canvas.
• Medium sandpaper.
• Fine sandpaper.
• Lint-free cloth.

This assumes that you have either a pre-stretched canvas or know how to do it yourself, but stretching a canvas is a different subject entirely. Now, you don't really need to stretch the canvas first, but it is highly recommended. The drying gesso will tend to shrink and curl the canvas if it's not stretched.

1) Pre-Sanding. Lightly sand the canvas with the medium sandpaper to take off the worst of the roughness.

2) Clean. Dry brush the canvas to clean off all of the sand grit and raw canvas fibers.

3) Gesso the Canvas. I have used Liquitex acrylic gesso and I usually like to thin it down a bit by adding 10–25% water. This makes it easier to brush on and keeps the gesso from drying too quickly on your brush. Be sure to work the gesso into the canvas thoroughly, filling all the crevasses and soaking all of the fibers.

4) Let it Dry. Acrylic dries relatively quickly, but I would suggest you let the canvas dry for an entire day the first time out. You don't want to be sanding any wet gesso. Subsequent treatments you can let dry for a shorter period of time—say as little as an hour.

5) Sand the Surface. The first treatment or two, you should use the medium sandpaper to get the worst of the bumps and fibers off with the least amount of effort. Subsequent treatments should use the fine sandpaper to make the surface smoother.

6) Clean. Dry brush again to get the sand grit and fibers off.

7) Repeat. Repeat steps 3 through 6 as many times as you feel is necessary. In other words, repeat until you have the kind of surface you want. Personally, I like the effect after gessoing with four coats.

8) Wash. Clean the finished surface of all remaining dust. You can use a lint-free cloth and a little water to perform this chore.

And you're done. Your canvas has now been gessoed or primed. Happy painting.