The impasto technique of painting means that the paint is typically laid onto the canvas thickly. This thick globbing allows every stroke of the brush to be seen in the paint itself. This also allows the artist to mix colors right on the canvas. Vincent Van Gogh is an artist that used the impasto technique often in his later paintings.
The word “impasto” comes from the Italian word “pasta”, to paste. This is the heart of the technique. The paint is pasted onto the canvas, and then spread with the brush or the painting-knife. It creates a texture and look that no other technique can create, leading to its widespread use to get unique feelings to paintings that can’t be see in reproductions.