This is the point in the process that most people seem to be curious about, at least judging by the number of questions I frequently get. Every stage in the painting is important, and it would be improper to say any one is more so than the others... but this is the most important stage. Although these articles are mostly geared to the non-artist, it does seem appropriate here to go into greater detail; please forgive the technical language.
First, a little background. I couldn't quickly find any reliable information about it's origins, but as a technique, underpainting is old - very old - reaching deep into the antiquity of painting. It consists of the artist applying a thin initial layer of paint onto the surface, over which successive layers are applied. It functions as the foundation of the paint strata, and can be an invaluable aid to the progress of the work.
My first exposure to underpainting was during my studies with Dennis Cheaney, who uses a color wash technique. This consists of applying extremely thin, transparent layers of full color paint (albeit without the use of white) over the drawing on white canvas. After it fully dries, thicker opaque layers are applied, of course now with white. This is basically a watercolor technique, using oil paint drastically thinned with turpentine. Though this works very well for some, there are a number of things I dislike about it, in particular the fact that it's difficult to correct, and it makes application of deep transparent colors problematic (the tone of the canvas easily shows through).
I began to experiment with monochromatic underpaintings, using a mixture of raw umber, black, and white; this is the method I use today. It solves a number of problems for me, including providing a stable base for dark transparent colors. A number of other things appeal to me: It gets me thinking about the values (the lightness or darkness of the colors). It's always best when you can split a problem in two, and this approach lets me separate value from color. It also starts me concretely working with the forms of the objects and the way the light flows across them. The result is a map that I'm working with when I apply the final color layer. Essentially, what I do with the underpainting is a dress-rehearsal for the rest of the painting.
The level of detail and accuracy I work with in an underpainting varies from piece to piece. In principle, I feel that accuracy is important in any stage of the work, for no other reason than to maintain care and alertness. However, I don't always apply that rule in practice, and often enough a few broad gestures suffice, even in passages that will be highly detailed in the final work. For this painting, however, it did seem important to delve into the detail, so I spent a number of hours finishing it (see below). Also, I don't generally find it necessary to match the values precisely (particularly on the darker end), and often enough the underpaintings have a poster-like appearance. It's a guide, nothing more, and the true values are worked out in the application of the color layer.
Underpaintings the way I do them are known as grisaille. They can also be executed in green hues, in which case they're known as verdaccio. I had real help in beginning to use this particular technique from my friend Stuart Dunkel. Before I knew him, he manufactured and sold grisaille paints graded to the Munsell scale. Since he no longer offered them, I experimented with mixing up my own batches. Although this was interesting and worked well enough, I really didn't have a lot of interest in sticking to that formal of a system for my own work. These days, I simply judge the value quickly by eye and move on.
On a final note, I should mention that not all artists employ this technique; far from it. In fact, I'd venture a guess that only a small minority use underpaintings; most prefer direct application of the paint without the initial steps I've gone through. However, for those artists working in and around the world of realism - particularly classical realism - it seems to be more or less the norm. Personally, I feel it's one of the most important tools I have; I could not produce this kind of work without it.
Now that the underpainting is complete, it will dry for several days, after which another layer of retouch varnish will be applied. Then, it's on to the final stage, the color layer. Finished paintings have been rather thin on this blog lately, which is ironic since I now have a small shelf full of them. I'll make it my goal for later in the week to photograph them and post them here.
Labels: How a painting is made