FRAME SIZE LAB
THE DIMENSION TOOLKIT

Mat & mount sizes

See how the full artwork, visible window and outer board relate in common combinations.

Original examples using ⅛ inch overlap per edge. Border values extend to the outer board edge.
ArtworkOuter boardWindowSide / top border
4 × 68 × 103.75 × 5.752.125 / 2.125
5 × 78 × 104.75 × 6.751.625 / 1.625
8 × 1011 × 147.75 × 9.751.625 / 2.125
11 × 1416 × 2010.75 × 13.752.625 / 3.125

These are examples, not universal pairings.

The window is determined by your chosen overlap and what must stay visible. Borders may be equal, unequal or deliberately bottom-weighted. Signatures, decorative sheet edges and printed margins can change the desired window.

Mat in the US; mount in the UK

In these guides, both mean the window board around the artwork. Suppliers sometimes use “mount” for backing or a different presentation method, so check the actual component and measurement diagram instead of relying only on the word.

Order terminology matters: some suppliers ask for artwork size and deduct overlap automatically; others ask for the exact visible window. Confirm the convention before placing an order.

Calculate a custom opening or plan multiple openings.

A visual size estimate. Verify the actual artwork, frame, mat, glazing, hardware, wall and manufacturer specifications before buying or arranging a display. Dimensions alone do not guarantee fit.