The term 'Artist Medium' can be summarized as a combination of two words: Gesso (5 letters). Gesso is a type of paint medium used by artists to prepare a surface for painting. It is a white, chalky substance made from a combination of plaster of Paris, chalk, and glue. Gesso is often used as a primer before painting on canvas, wood, or other surfaces. It provides a smooth, even surface for the paint to adhere to and helps to prevent the paint from cracking or flaking off.