Plastics

acrylic designs
An acrylic fabricator with a good amount of useful info on their site
acrylic spheres
alsa corp | fxsheeting
Interesting laminates.
alumilite
casting resin
A nice description of the resin casting process
cyro
This is a massive knowledge base with an awful interface
delvies
Good online source for cell-cast acrylic sheet, and fabrication supplies. A one-stop shop for hobby acrylic working.
harvel plastics, inc.
Source for clear PVC pipe and fittings in schedule 40 or schedule 80.
modern
onsrud cutter - plastic routing
Specialized router bits for cutting plastic
plastics distributor and fabricator magazine
regal plastics
Here's an unbelievable library of plastics information, especially the acrylic catalog. It's like a textbook on working acrylic
ridout
Some useful plastics info
sdplastics
One of the worst looking sites I've ever seen
tap
lots of composites as well as plastic
us plastic
US Plastic has almost everything