Or at least translucent to visible. Hopelessly undiscriminating IR encoder &
decoder on a piece of kit but need to see the LED segment display , which
inconveniently has the IR Rx within it.
I've tried loads of normal materials like polythene,perspex, glass, mica,
silicone rubber.
I know black polythene will transmit the IR of PIR units and block visible
but there is more seperation of f there