I prefer matte black Rustoleum for most of my tanks. I enjoyed the cork thing when I did it and am pretty fond of my 20L with the wood/foam background. I guess it all depends on what I'm trying to accomplish.
Cork=natural or Dutch
I like plain color backgrounds, IMO. I think they look more classy
than Greek ruins, rock crystal, saltwater reef pictures, etc.
I have seen well done tanks in many colors: yellow, red, blue, white,
black. Yellow was especially beautiful in an ADA aquascape titled
"Little *****" with cardinals and altums. The deep yellow color reminded
me of the tannic acid stained waters of the Rio *****.
Currently, my 55g has a sky blue background, and I think I may go with
white on my 20g long. I'm not too crazy about black. I feel that a black
background is kind of like omitting the effect of the background on the
aquascape. Yes, it makes the plants stand out better but it doesn't
really evoke anything...
Background color will definitely be a future "weekly topic." I'll post
some examples at that time.
Contact film here. Why? You can change it in the future as opposed to paints. It provides a very good uniform color. I don't particularly like artificial backgrounds unless I'm doing a biotope aquarium.
I have a light blue one on my current tank. Not sure about the yellows, reds or whites though. Guess I'll wait to see how Carlos' come out.