I am reposting this from another thread, since it is a sizable reply that probably merits its own discussion, and that I will update with my results - I figured thread hijacking probably isn’t too polite Original thread at http://nuigroup.com/forums/viewthread/4706/
I was recently in “Menards”, a US (midwest?) home supply store/construction store/basically something kind of like Home Depot looking for useful multi-touch parts, when I stumbled across a potentially great find. In the window section, they had eight-foot long strips of vinyl (stiff plastic) labeled “drywall receptor” that was more or less in a lower case h-shape (apparently used for installing vinyl-frame windows). They stocked a variety of widths, and each 72” (six-foot) segment was around four dollars, except for one, which was eight dollars. (US dollars). I seem to also recall seeing a similar shape, though not quite the same thing (more of an _|- shape if you can imagine that hypen at the top instead of in the middle - do I call that an S shape?), in steel for about the same price on an earlier trip, though it wasn’t in that section, and I couldn’t find it again in the limited time I had to browse.
Also, in what I believe was the door section, although my notes say it was a different window section, I found a similar item, but in a the wider variety of shapes, all 8 feet long, and all around three dollars or less.
Some of these items had a fairly deep channel, and certainly deeper than the aluminum U-channel they also stock.
I had a couple application ideas for these items. They could be used to mount an acrylic sheet, with or without a strip of LEDs on the edge. I think they might also work in an LED-LP system to make the infrared frame, and also perhaps an LLP if lined with an absorptive material for the laser. While I don’t think I’ll be able to test the LLP system, I anticipate trying them in an LED LP system and will share my results on the forum.