Quoted from Frax: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.
I stuck mine directly on my ColorDmd.
It cut the glare from this and also from LED strips I have at the back of the playfield.