Yep, these have been around for a good while, but it took forever for one or two guys to finally make them available at reasonable prices. The microlouver film is not cheap, so bulk purchasing is pretty much the only way to use it for this application.

I've always installed mine directly on the DMD glass. Obviously not an option with the LED DMDs, but the inside of the view window works best in that case IMO. These things are seriously exponentially better than the "bent plastic" thing, which is a real kludge.

Only if they're 3 feet or 9 feet tall, for the most part.

Keeping in mind that my experience is with other sellers, NOT with Art/Comet's *specific* product...

You mean aside from the fact that the bentplastic are a cheaparsed kludge that fall out every time you need to remove the glass? I bought one, exactly one, and it's annoying as hell to grab the thing, set it aside, and put it back in place. Meanwhile, the 3m film is installed, stays where it's supposed to be, and doesn't get in the way of me working on my games. Oh, and it doesn't look absolutely ridiculous either.

They 3m film doesn't dim the DMD very much, if it's installed on the DMD or the inside of the plastic. My personal recommendation, due to the doubling effect shown above, is to install it directly on the DMD anytime it's possible, and second option on the inside of the speaker panel. I would not ever install it on the outside. Anytime I've ever bought these kits, from two different suppliers, they've come with double-sided 3m adhesive that's maybe 1-2mm thick and transparent. It's easily removable and you would just need a few small strips to place it on a new one.