Actually, roofing shingles have a very high friction coefficient. So, using shingles will actaully defeat the purpose of trying to slide on skis. I would suggest something slippery.
lol lack of knowlege? I've built several of my own boxes using everything from plexiglass, PVC, lexan, sheet metal, and puckboard. I think i know a little about it. I was going to say sandpaper, but i thought roofing shingles would be funnier. I'm glad you feel more intelligent than me though. I hope it continues to work out for you in the future.
hahahaha so far we have carpet, roofing shingles, something about some sort of bar, and a bunch of sarcastic comedians. This is looking up to be a good thread.
or HDPC(High density polycarbonate) will also work too... its the clear stuff I think whereas the HDPE is the white plastic... similar or the same as puckboard... not quite sure