Putting it on thick

I am having my students stencil plaster onto their canvases for a little added texture.  We have been looking at Wayne Thiebaud's cake paintings, and are inspired to paint sweets in acrylics.  He used oils, and was able to get them richly thick. A little plaster under acrylic goes a long way. Above is one of my demo. paintings.

Student applying plaster through a stencil- don't ask me about the phone.