Believe it or not it is Christmas wrapping paper. I wanted red and black, saw that laying around, and presto! I need to re-do it as the kids ripped it a bit on the corners when they were younger.
Ya'll got some nice wood. Here is 2 of mine. Last one is my 20 gallon planted tank. There is actually a lot more wood in there than you can see. Java moss is ruthless. The wood was all collected locally.