A primer is a preparatory coating applied to a surface before painting. It is most commonly used on any surface which requires the extra preparation to allow the paint to bond with it. With the increased adhesion that it provides, the paint’s durability is greatly increased and produces a much better finish.
Gesso is a calcium based (Whiting) primer that allows oil and acrylic paint to bond with canvas, wood, paper and a range of other supports or surfaces. It is available in a range of colours and clear preparations or can be made from scratch with Whiting and Rabbit Skin Glue. All good pre-made canvases are already primed with a number of coats of Gesso.