Rosalind Krauss is visiting ... via 2 of her books. I have a feeling she will be here for a long time, as she has a good deal to say.
Then the question of layers ... I read an article today by Simon Abrahams, who writes the blog at "Every Painter Paints Himself." The article discusses two paintings by Manet ("Le Déjeuner sur L'Herbe" and "Mlle. V in the Costume of an Espada"), centering on the question of the different picture planes, and the different types of brushwork in each work. Read the article; here is the short version: http://www.everypainterpaintshimself.com/essays/manets_le_dejeuner_and_mlle._v._simply_explained/ The article is of a piece with his website, which also, by the way, has a splendid gallery of images, arranged alphabetically by painter.
And here is a close-up of a layered work I am just starting: