Designed by a photographer, MatCutter2 is a simple tool that quickly provides the measurements you need to cut your own mattes.
Handles over-cuts (so some paper around the image shows) or undercuts (so the matte overlaps the image a tiny bit).
Offers an optional and unique automatic proportional overcut, so that the cut matches the size of the image.
Works with inches or centimeters (imperial or metric) measurements.
If this software prevents one bad cut, it will have paid for itself.
Fast, convenient and easy.