You need to use the thicker stencil plastic for this. I had to do it in stages. I used a putty knife to apply Joint compound left over from building our house though you could probably use modeling paste or something like that I suppose. The joint Compound sets up quickly and you can over lap it in layers to get more depth. I haven't sealed it or painted it as it dried white. I've done this in the past on wood too and it's stayed where I put it looking nice for years. Gives a nice faux embossed look to things.