3D Background?? Is it possible?

[dsaundry]

So what type of cement paste do you use? I thought about using a mold of some type with that pond foam you can buy and adding sand to it to get a nice texture. Once it hardens you could cut it for intakes etc and shape it for your tank using egg-crate. Does that sound feasable? If not, what about a D.I.Y. live rock mix in a mold??