This is a Durable plastic that is made for Resin Casting. Pieces pop out easily-May have a few water marks, but a thin coat of resin or resin spray will take care of that. these ribs measure approx 2 1/2" tall each and are very detailed. Deep cavity for easy filling. Do not put in oven. Pieces made using this mold can NOT be used to remake into molds for resale. Molded From Love 2015 All Rights Reserved.