Priming and Surface Preparation

Felice House, a painting professor at Texas A and M, says: "Just today a student came to me with a question about how you prime your surfaces. We looked through the blog but couldn't find details. If you can fill us in that would be really helpful."

OK, Felice. Let's talk plein-air oil first. Before I leave home to go painting, I prep a bunch of panels in advance. That way the priming is dry when I'm ready to start. 

I use Masonite or wood panels. The wood panels are typically birch plywood panels with canvas glued to them. I start with a coat of gesso. Then I cover that with a Gamblin oil ground. With its alkyd resin binder, this oil priming takes a day or two to dry. Putting a couple drops of cobalt drier speeds the drying time.

Typically I'll mix the oil ground with burnt sienna or English red oil to give it a light brown or pink tone. Here's a study where I left the priming. Sometimes I'll tone a panel to a cool color—bluish or grayish. I often choose to prime the board the complementary color of the landscape I expect to paint. 

For those who aren't familiar with oil priming, it presents a more impermeable surface to the paint you apply in the field, so the paint floats on the surface more. Oil priming is rather slick and shiny, though, and doesn't take well to pencil or charcoal, so I just do my drawing with the brush.

In addition to Gamblin oil ground, there's Williamsburg oil ground. Both use titanium white for the pigment. Some artists prefer a lead white ground, which is OK as long as you're fully aware of the health risks.

Many people prefer to paint over acrylic gesso priming alone, without the oil ground. This allows for a pencil or charcoal underdrawing. But for field sketches, I find gesso too absorbent, which is why I like the oil priming.

When doing a painting in the studio, such as a smaller Dinotopia painting or a science illustration, I'm working in oil, but I have to start with a very careful pencil drawing on illustration board. For larger Dinotopia paintings I do the drawing gesso-primed canvas covered plywood panels. The gesso priming reduces the canvas texture so that it's not so insistent.

After doing the pencil drawing, I need to prepare the surface for subsequent layers of oil, so it has to be sealed first. Otherwise the turpentine would melt the pencil.

I use workable fixativeand acrylic matte medium to provide that impermeable layer. It's also possible at this stage to pre-texture the surface with acrylic modeling paste to give the paint more surface texture, even if the oil is applied thinly over this priming. This is my secret for using oil on jobs that require short deadlines.

I demonstrate this method of priming on my recent tutorial: Tyrannosaurs: Behind the Art.

You might want to check out my previous post about the Dinotopia priming technique. Also, my book Imaginative Realism: How to Paint What Doesn't Exist covers many of my technical methods. And please have a look at my earlier posts on Constable's Oil Painting Materials and Warm Underpainting