Thank you, Karin, for your reply. I mentioned the David's unfinished portrait at the Art Institute in Chicago, because it's an example of the classical technique. He only did the underpainting because he had to go on exile during the political turmoil of the French Revolution. This underpainting is done with very thinned pigment, almost watery and in a very light value, because the values get darker with each application of glaze. What I don't understand is how they painted the flesh using the glaze technique.

I don't have a photo of the painting to scan it.

Underpainting
 

Tito,

Michael Georges, a member of the Forum, studied under Frank Covino, who teaches the glazing technique or the Grisalle method. Frank has a web site and you can order his book from the site. It is very informative, and I refer to it often.

The title of the book is "Controlled Painting". I believe it is out of print, but you can get a photo copy of it. Unfortunately it is not in color, but it is very detailed. The web address is www.portrait-art.com.

He also discusses glazing in great detail and Verdaccio, a toned greenish underpainting using nine shades of paint mixed with white, ivory black, and terre verte.

Hope this helps.

Thank you so much for the tip, Alicia.

It's a pity that the classical painting tradition was allowed to die off in the 19th Century.

I really need to see this in order to explain it. Did you try a Google Image Search on Jacques-Louis David? http://images.google.com

It is very possible that you are not looking at an underpainting at all, it might just be the way David blocked in his drawing and design of that portion of the painting.

The way you have described this, the next step would NOT be adding flesh tones by glazing.

Tito,

I have to agree with Karin.

The monochromatic underpainting is used with both glazing and opaque application of paint. Since flesh tones contain so much white, glazing them is not a very effective way of proceeding. As I indicated in a previous post, glazing is most effective with darker transparent or semi-transparent colors.

To your point about glazes darkening the area, you are correct that repeated glazing does darken the passage. If I have a passage that I intend to glaze more than once, then typically I will raise the value of that passage by 1/2 to 1 full value in the underpainting to accomodate the glazes.

I just bought a tube of Gamblin's Asphaltum and I plan to experiment. Can William Whitaker or Karin Wells give some tips?

Another question, can a warm background be used in a portrait, and under what conditions?

Thank you in advance.