Some kind of plastic needed

[Musht]

Could try theatre colour filter, gel, not self adhesive though , sandwiching in between 2 layers of clear acrylic works at a push.

[D.C.]

Could try theatre colour filter,

This stuff might work

FILTER GEL SHEET 48 X 21 STAGE LIGHTING VARIOUS COLOURS | eBay

If not you could always try rear projection film, that will definitely work.

[m_c]

I think I may have some OHP sheets around somewhere. I'm currently wondering if a layer of vinyl, then a more opaque frosted perspex would work better, as I've just been doing some searching, and it seems frosted vinyl only comes in light/pale colours.

One goal I want is an anti-glare finish, which is best acheived with a dark satin/matt/frost finish.

[martin54]

Either matt or translucent vinyl would do you, no need for frosted acrylic

[martin54]

Just a thought as I was sitting here this morning. Is it just the glare that is causing problems? If so have you tried a clear matt laminate? Clear laminates are used over digital prints for a number of different reasons, they are basically a clear vinyl but available in gloss, Matt, satin & crystal finishes.