I don't know what it's called. Some people put backing on their tanks. I have a roll of black on one side/blue on the other. I thought the black would look striking with the fine black gravel. But I'm not in it for the asthetics; I'm in it to care for a special fish who depends on a human. I want to be the best human for Fishy Boris. Ok, I got off on a tangent. My question, finely put, is does a betta prefer looking at a blank white wall, a sort of mind-numbing infinity? Or does s/he like the safety, the invulnerability, of a finite space to live in? How do you feel/what do you think of this aquarium wallpaper? (I hope I've made sense.) Cross-posting to Aquarium Builds.