Painting back wall

[Funky_Fish14]

A friend and I used a double layer of Limo Tint on the back of his tank to black it out. But as a response to DiverDude:

You can get sheets of vinyl in black or blue or whatever colour that you apply in the same way as you would window tint. It makes a really smooth finish. I used to work at an aquarium manufacturing warehouse and we switched from using krylon to this vinyl on the backs of tanks.