Where To Find A Background Cling?

[DiddleBug]

I'd like a nice back ground cling for both of my 10 gallons.  I like the "rocky" look, or the 3D rough-edged stone.  I've looked around for some but I can't find any.  Is there a place online to get some?  Where do you get your clings?  

 

[FriendlyFriendlyFish]

I recently bought a cling at PetSmart, I went with black but they had lots of different ones. Watch out when you buy one because when I got home I realized that the special adhesive they sell is sold separately