Just as long as the finished product meets all the design requirements, it is possible to use any foam and any foam building technique to build up and carve or pattern the desired shape. For foam patterning rigid foam is primarily used for the positive sculpt. The foam surface would be sealed to add durability and then painted with a brush, airbrush, or sponge. It can also be covered with faux fur or fabric. It is very useful for detail pieces such as the bear's nose. Blue extruded polystyrene or polyethylene foam can be sculpted and sanded then covered with scrap fabric and glue. Many foam artisans' use open-cell upholstery grade foam to produce really wonderful masks, puppets, costumes, and props. It carves well with electric knives, razor blades, and scissors it is possible to get quite a nice level of carved detail too. In terms of finishing, it takes spray paint and airbrushes very smoothly.