usplastic.com has it. go to the sheets and whatever section, it's under the styrene catagorey. They have the measurements for thickness inches. I think .90 is about 1/8" thick. Also look in the phone book for any plastic dealers near you. You may be able to get it cheaper form somewhere locally. Here in Kansas City I go to Fantastic Plastics and can get supplies cheaper there. I know that doesn't help you, but it might help someone.