Mat Cutting

[that-redhead.livejournal.com]

I have recently completed some cross-stitch pieces, which are unfortunately odd sizes for normal size frames. Instead of buying more expensive frames, I decided to buy a larger normal size frame and a mat to fill up space in the larger size frame. What is the simplest way to cut a mat to fit a frame? I'd prefer to do it myself, since I'm trying to save myself some money. Are there special mat cutters that aren't too expensive? Can I use a box cutter or utility knife?

Pictures of projects to come soon, gotta wait for my camera battery to charge :)