 The trowel is then run over the surface of the drywall, knocking off the stalactites and leaving the mottled finish.A much more common, and faster technique is to apply the texture mud (which is slightly different from joint compound, in that it has less shrinkage upon drying) with a texture machine – a compressor and a texture spray hopper which sprays mud instead of paint.This applies what is referred to as a splatter coat.