Plan your picture mat.

From a sheet to a clear plan.

First measure the actual paper and record the part covered at each edge. The exact window subtracts both opposite coverages. Then either enter a known board outside size or choose four visible borders and build the board outward from the window.

A check a window alone cannot make.

The paper extends behind the window. Each board border must contain the coverage on that edge, or the paper would extend beyond the outside board. This model rejects that placement even when the smaller window appears to fit.

Try a verifiable example.

For 8 × 10 in paper, 0.125 in coverage per edge, and an 11 × 14 in outside board: window = 7.75 × 9.75 in; borders left/right = 1.625 in, top/bottom = 2.125 in. A 0.5 in extra bottom difference changes top/bottom to 1.875/2.375 in while keeping the window unchanged.

After updating, download or print the worksheet. It names exact window, outside board, paper, coverage, borders and units. Editing an input removes the old result until you update. Returning from the visibility tool carries the protected-area geometry into your worksheet. Editing the paper dimensions clears that carried check; measure it again. Check important details next, then read the order checklist.

What the tools do not decide.

They do not choose a suitable coverage amount, mounting method, material, minimum cuttable border, bevel definition, practical clearance or stack depth. Confirm those with the supplier for the actual object. A zero-coverage example is not a securing method. For valuable or sensitive originals, seek appropriate professional advice.

Measurements stay in this browser’s page memory. There is no upload, account, saved project or analytics script. Download a note before leaving if you need a record. Links between tools carry measurements in a URL fragment; no cloud project is created.