Gesso

Gesso is a ground that prepares a surface for painting, gilding or other decoration. Traditionally it combines a white mineral material, such as gypsum or chalk, with a glue binder. The Italian word means gypsum, although art descriptions use the material term more broadly.

Ground and shaped decoration

On wooden panels, gesso can provide an even surface for paint or gold leaf. The National Gallery describes coarse and fine layers in traditional Italian preparation. It also notes that panel paintings north of the Alps often used chalk grounds instead of gypsum. Distinguish the function of a ground from a claim about its precise mineral composition.

Gesso can be built up into low relief and incised with details. Some picture-frame decoration may therefore be shaped in the ground rather than carved directly into the wood. A white exposed fracture alone does not establish the material or the frame's age.

Modern acrylic gesso

Products sold as acrylic gesso use an acrylic polymer binder. Golden Artist Colors distinguishes these materials from traditional glue-bound gesso. The name on a modern container is therefore not a precise formula for the ground in an older artwork.

Before assessment or treatment

Practical suggestion: Photograph existing losses and record loose layers without scraping new test areas. Clarify conservation and restoration before repainting or repairing an older work.

Explore art at OBA, or send photographs of artworks and frames for assessment and possible purchase.