Description

Mat & Margin is a free picture-mat planner for artists, photographers and framers who need a clear set of measurements before they cut a mat or fill in an order form. It is an independent planning aid for flat paper and one rectangular opening. It is not a frame shop, and it does not certify cutting tolerances, frame fit, mounting or preservation safety.

The site starts by separating three measurements that are often mixed together on order forms: the physical paper, edge to edge; the window, which is the opening that shows the art; and the mat outside, which is the full board that fits inside the frame. Coverage is how much paper the mat hides at each edge; a border is the visible board from the window to the outside edge. A worked homepage example uses an 8 × 10 inch sheet with 1/8 inch coverage on every edge, which produces a 7 3/4 × 9 3/4 inch window on an 11 × 14 inch board.

You enter paper width and height and the coverage at each edge, then either enter a known outside board size or choose four visible borders and build the board outward from the window. After you update the result, you can download or print a worksheet that names the exact window, outside board, paper, coverage, borders and units. Measurements stay in the browser; there is no account, upload or saved cloud project.

A visibility check lets you mark a rectangle inside the paper that contains every detail you want to keep, such as a signature or edition number, and then see whether the planned coverage clips that rectangle. It reports the visible fraction of the rectangle, not a recognised image, and a “within” result is not a safety approval. The tools do not choose a suitable coverage amount or mounting method. Final fit still needs confirmation with the supplier or framer.