I bought a mount cutter set on ebay that included a plastic cutter, a cutting matt and the guide ruler. The cutter was terrible but I then managed to get a used Dexter mat cutter on ebay for about 9 quid. They are excellent. Cutting the mounts well is quite easy but marking the right size cutting lines is abit hit and miss for me. If I am tired or get interupted while marking it tends to go very wrong. It is still a bit hit and miss for me though, you really need to plan the image and border size (made by the matt) properly or it doesnt look good no matter how good the image and the cratsmanship of the matt cutting.