I wanted a special size too and didn't want to use the thin plastic. Our local hardware store doesn't offer cutting service, but said we could score the plexiglass with a utility knife and it would break clean. So I bought a small sheet of plexiglass to try it. Well, the scoring/breaking didn't work very well. Then we tried a jigsaw and it worked great. I got the boys in the house involved - they love any excuse to get out the power tools.
Donna