From the archives:
One of my favorite things to do with oil pastels is to lay down thick color then draw back into it with some handy implement or other. Sometimes the first layer is scraped, then a second color is heavily applied and scraped into revealing some of the first color. When I took a drawing class at Western Connecticut State University, many years ago, I remember learning to draw into heavy pencil marks with an eraser. This is where I got the idea of removing material as a way to form the picture.
Post Script 10/19/2011 - One of the reasons I reposted this at this time is, I recently read how Jay Defeo formed The Rose using sharpened knives as much as brushes as she cut back into the layers of paint and scraped and hacked to remove material to form the topography of the painting. Very cool stuff.