My last few sheets of styrene have come from old transit bus signs. They are 2' x 8', 0.060" ("sixty-thou") thick. They take a bit of washing up, and sometimes the vinyl lettering needs to be removed. But best of all, they are free!

At 60-thou, they are a little thick for "fine" work, but they make great roads, parking lots, internal braces for large buildings, roofs, and so on.

So check with your local Transit Authority.


Andrew