I bought a great board border that's sort of 3-d. It like pops out. It's awesome but it constantly falls down!! I have tons of masking tape on it and it just won't stay up. Most of the stuff I put on the wall I have to use double sided tape for it to stay (I think because of the type of paint they use), but I don't want to waste a whole bunch of expensive double sided tape to stick the border up. Plus it's so light it should stay on its own, right? Any other ideas to keep it from falling down? Walls are cement. Thanks!