A thin, transparent film of color is painted over another dried color, modifying both colors.
This blended effect is entirely different from that in which two colors are mixed together on a palette.
(Think red mixed with white makes pink, but glazing red over dried white makes a bright, luminescent
red). Glazing not only changes a color, but deepens it. When glazing, painters think about how to set-up
the final glazes by using disparate colors in the underpainting. Glazing is also used to unify diverse
values and marks under one hue. Traditionally, glazing is done from light-to-dark, taking advantage of
the white of the canvas (or luminosity), which reflects light through the transparent glazes. "Light
penetrates this glaze, bounces off the opaque underpainting beneath, and is reflected back up through
the glaze. Painted objects thus seem to reflect light as if they were real, and the play of light through the
painted surfaces gives them a sense of tangible presence." (Henry M. Sayre, "A World of Art", 1994, p.234-
5). Glaze is usually applied sparingly with a soft brush, and then patted or spread with the tip of a clean,
dry brush to spread color uniformly and pick up excess color.