This article is from the Car Audio FAQ, by Ian D. Bjorhovde (email@example.com) with numerous contributions by others.
A good quality Carbide Tipped Triple Chip saw blade is preferred when
cutting Plexiglas. This reduces the amount of chipout on the opposite
side of the material and produces a smooth edge.
A Router can be used to cut Plexiglas as well. The Router should be at
least 1.5 HP or better and with changeable collets for a 0.5" Shank
quality 2 flute Carbide bit. This reduces the vibration and chattering
when cutting and will produce a more smooth edge.
Since Plexiglas is an acrylic plastic (polymer), heat generated by the
saw blade or router bit when cutting will melt the material and create a
glazed imperfection viewed from the face if you do not maintain a steady
rate of cut. It is best that when cutting you do a rough cut first,
then do the finished size cut to reduce stress on the cutting blade and