Final answer:
Gesso is a type of primer or ground favored for tempera painting. It is made from a base of white pigment, chalk, and a binder. Modern gesso uses acrylic polymers and latex for added flexibility.
Step-by-step explanation:
Gesso is a type of primer or ground that is favored for tempera painting. Traditionally, gesso was made from a base of white pigment, chalk, and a binder. It was used to prepare the base on wood panels or canvas before applying paint. Modern gesso uses acrylic polymers and latex, which provide more flexibility when applied.
Unlike other painting mediums, gesso is specifically designed to create a non-porous layer between the support material and the painted surface. This helps to prevent paint from seeping into the support material and weakening it over time.