Gesso whiting refers to a fine, white powder—typically calcium carbonate [chalk]—that serves as the primary filler and bulking agent in traditional artists gesso. While modern acrylic gesso uses polymers, traditional gesso is a mixture of whiting and an animal glue binder, such as rabbit skin glue. Key Characteristics Functions * Composition: It is made of finely ground chalk [calcium carbonate] or sometimes marble dust. * Purpose: It provides tooth [texture] to a surface, allowing paint to adhere better, and fills the wood grain to create a perfectly smooth, hard base for gilding or painting. * Versatility: Beyond gesso, it is used for degreasing metal plates in printmaking or as an abrasive for polishing. Preparation Tips * Sieving: Always sift the whiting into the warm glue through a fine mesh strainer to prevent lumps. * Avoid Bubbles: Stir gently with a spoon or brush whisking introduces air bubbles that can cause pinholes in the dried surface. * Temperature Control: Heat the glue in a double boiler. Never let it boil, as this destroys its adhesive properties. * Consistency: Aim for the texture of single cream. If it is too thick, add a small amount of warm glue solution or water.
