One of the unique advantages of oil paint is its ability to be layered. Artists can build up thin, transparent layers called glazes to create depth and glowing color. Glazing is often used after the opaque layers have dried. Each glaze adds richness and subtle color shifts that are difficult to achieve with direct painting. However, glazing requires patience because each layer must dry properly. When done correctly, layering and glazing give hand-painted oil paintings a luminous quality that has fascinated viewers for centuries.