An engineer friend introduced me to the virtues of ABS plastic, which is extremely strong, does not splinter when you drill or saw it (unlike wood or acrylics), comes in a variety of thicknesses of 4×8 sheets (just like plywood), and usually is smooth on one side with a textured finish on the other. We use it to make everything from little brackets and shelf supports to complicated containers for transporting fragile equipment. You don’t have to paint it, and its consistent texture makes it very easy to shape. If you live near any large urban area, there will be at least one plastics supplier near you that will sell it to you by the sheet.
The best part of fabricating things with plastic is that you can bend the plastic. When you work with wood, you have to join two pieces (mitering, gluing, whatever) to make a right-angle. With the FTM heating device, I can make a controlled bend within a couple of minutes. Sponge it with water and the plastic stiffens, seemingly just as strong as before. It’s like large-scale origami.
Other plastic benders may be available online, but the Cool Tools Rules state that I may only recommend the tool that I have used personally. So, this is it, even though I must warn you (shock! horror!) you cannot buy this online. You can visit the manufacturer’s web page and view the specifications, and then if you want to purchase your own bender, you’ll have to pick up the phone and order it, with your credit card, from a human sales person.