Yep I must agree, I have recently been using a lot of plastics. Mostly recycled reconstituted polyprop sheets and I love the stuff. It routes smoothly. Is reasonably ridget, is cheap, has extreme chemical and moisture resistance and not subject to rust or corsion. Much cheaper than Alum, but less ridget than alum, however you just make the design thicker.HDPE (High Density Polyetheline)