Mat Board

A mat (or mat board) is a window-cut piece of thick cardstock that sits between the artwork and the glazing. It serves two purposes: visually, it gives the art room to breathe and signals formality; physically, it creates an air gap between the print and the glass, preventing moisture-based damage.

Mats range from 1.5" (narrow, minimalist) to 4" (generous, museum-style). The standard for residential framing is 2"–3" on all sides, with a slightly larger bottom margin than top to counteract the optical illusion that makes centered mats look off.

Archival mats are acid-free and made from 100% cotton or alpha-cellulose — critical if the artwork is valuable or made on archival paper. Non-archival mats leach acid over time and yellow the edges of the print.