Double mat calculator
One board size, two windows. The reveal is the inner mat showing around the opening.
Result
Package / glass 16" × 19 1/2"
Mat window 11" × 14"
Finished outside 18 5/8" × 22 1/8"
Sight opening 15 5/8" × 19 1/8"
Your dimensions will carry over. Add your own artwork next.
- Artwork11" × 14"
- Window11" × 14"
- Window border · top2 1/2"
- Window border · bottom3"
- Bottom weighting1/2"
- Inner window10 1/2" × 13 1/2"
How it works
Both mats share the same outer size, so you still order one piece of glass and one backing.
The inner window is the artwork minus overlap. The outer window is larger by the reveal on every side, which shows a line of the inner board.
Bottom weighting stays on the outer borders. The reveal can stay even while the bottom border is taller.
Common mistakes
- Treating reveal and overlap as the same number. Overlap hides the print. Reveal shows the inner mat.
- Cutting the two windows from different centres.
- Forgetting the second board when you check whether the stack fits the rabbet.
Frequently asked questions
What is a mat reveal?
The strip of inner mat visible because the outer window is larger than the inner window.
Are both mats the same outer size?
Yes. They sit together in one rabbet.
Does a double mat change the glass size?
No. Glass follows the outer board.