Papier-mâché paste is the substance that holds the paper together. The traditional method of making papier-mâché paste is to use a mixture of water and flour or other starch, mixed to the consistency of heavy cream. While any adhesive can be used if thinned to a similar texture, such as polyvinyl acetate based glues (wood glue or, in the US, white Elmer's glue), the flour and water mixture is the most economical. Adding oil of cloves or other additives to the mixture reduces the chances of the product developing mold. The paper is cut or torn into strips, and soaked in the paste until saturated. The saturated pieces are then placed onto the surface and allowed to dry slowly; drying in an oven can cause warping or other dimensional changes during the drying process. The strips may be placed on an armature, or skeleton, often of wire mesh over a structural frame, or they can be placed on an object to create a cast. Oil or grease can be used as a release agent if needed. Once dried, the resulting material can be cut, sanded and/or painted, and waterproofed by painting with a suitable water repelling paint.