Impasto is a painting technique in which paint is applied very thickly to a canvas or other surface. It is most often done using oil paint, due to it's viscosity and the long amount of time it it takes to dry. However, it can also be accomplished to some extent using acrylic paint. In impasto, the strokes created with a brush or pallet knife are highly visible and at times even have a sculptural quality. Impasto is often used to catch the light in a certain way or to create other expressive qualities in a painting. It was heavily used by many impressionist and post-impressionist painters. Artists who used this technique include: Rembrandt, Monet, and VanGogh.