DAP Plaster of Paris Dry Mix sets in 20-30 minutes and can be painted with any oil or latex-based paint. It is preferred by professionals, artists and hobbyists. When using Plaster of Paris you will need clean cold water, a clean mixing container, putty knife or trowel, and sandpaper or a sponge. Read all instructions and warning before using. 8 lbs covers approximately 4.5 sq ft depending on thickness of patch.