Trimroc Interior Crown Moulding consists of interior acrylic modified gypsum-plaster moldings extruded over an expanded polystyrene base that is ideal for residential and commercial applications. The standard profiles range from a 4-inch face to a 12-inch crown, all constructed in one piece. The product will accept water, oil or acrylic based paints. Primer is recommended prior to painting. Custom shapes are available and the company asks for drawings and approximate lineal footage to be sent. The product does have a fire rating and ASTME-84 test results are available on request.