So with vivarium backing I've noticed a number of methods:
1. Bare black foam
I did this with mine. Just black foam. Looks pretty decent in my opinion. Kinda rock-like, can be unpredictable in shape.
2. Black or great stuff foam with silicone and coco fiber
In some tutorials the glass is coated with foam and then the foam is covered with silicone and dry coco fiber. Ive been thinking of doing this for my next viv.
3.exoterra etc premade fitted backings.

Which do you find easiest and/or cheapest to make? Which do you feel looks most natural?
Also, with the silicone covered foam with coco fiber, does moss grow on the backing? And can a pothos plant climb on it?