I elected not to use any water or moisture...the skins stick well enough without it. However I wasn't totally happy with the level of transparency...I tried and applied all three skins on the glass before I found a result that I didn't hate. I'll bet part of the trouble I encountered was due to my lack of skill at applying the skins, and perhaps due to not wetting the skins first, but if I'd known these required water I wouldn't have bought them.