It has to be obvious in some way that it's not actual money. People hand out coupons all the time that look like money but the coupons are the wrong size and clearly state that they're not legal tender. Each side of the bill has to have something on it that makes it clear that it's not real money if you want to give away the textures and not risk the Treasury Department getting really antsy. To be on the safe side, you might consider just giving out the prop with the UV Mapping and let people insert their own currency textures. (If someone managed to alter your texture to make it look legit, there's always that small chance you'd be blamed for giving them the tools to do so. Yeah, it's stupid, but you can't underestimate the legal system. Although giving out the nice side textures you have for the stacks wouldn't get you into trouble.) Nice job on the mesh, btw. Does it have a fold longways, like some people crease money to give as tips? Cheers!