just because i'm here and figure we should make the most of it . . . .

Starboard is a good product which is available at either marine stores or internet sales in small pieces & a couple of different thicknesses/ colors.

can be worked with hand or power tools. use heat to polish the edges.

Amazon.com: Starboard - 385983: Industrial & Scientific

another good material for projects, especially bag liners/ bottoms, is Kydex.

Amazon.com : kydex