Acrylic is a painting medium that uses an acrylic polymer emulsion as a binder for the pigment. For some, acrylic has replaced oil based painting. It has many of the advantages of oil painting without the drawback of drying time. Since it can be diluted with water it can have a quick drying time. However, that time can be extended if that is the artist's desire. Unlike watercolors, the dried painting is not as susceptible to water damage. For a more developed discussion click here.