Mat guide

Cover enough edge to hold the art—not the subject.

Overlap is the amount hidden under each side of the mat window. The frame planner subtracts twice that value from both artwork dimensions.

Choose overlap from the artwork

A quarter inch is a useful planning starting point for many flat paper works, but it is not a universal rule. The safe value depends on the paper edge, mounting method, image placement, condition, and expected movement.

1. Measure the physical sheet rather than the advertised print size.
2. Identify signatures, plate marks, deckled edges, borders, and important image content.
3. Check all four edges; do not assume the image is centered.
4. Choose the smallest overlap that safely retains the work.
5. Preview the calculated opening before cutting the finished mat.

For collage mats

Use a consistent overlap when photographs have similar safe areas. If one image has tight edge content, evaluate it separately before applying one value to the whole grid.