All Casa Sculpture molds are made by hand by employing either the pour method or brush-on method. Each of these techniques is a multi-step process which requires proper knowledge of the original piece to be molded and the final cast to be made from the mold.
Molds are typically made in urethane or silicone rubber with an FRP (“fiberglass”) backup, or “mother mold,” which supports the internal rubber mold. The type of rubber used is determined generally by the number of casts to be made from the mold. The FRP backup is the same for both urethane and silicone internal molds. High production FRP molds and single-use plaster waste molds are also available, depending on the project.
Plaster molds are adequate for one-time use. They don't usually survive beyond a single cast, hence their being referred to as "waste molds."
Urethane molds are good when two or three casts are desired. Molds in urethane are less costly than silicone molds however it is not a high production mold.
Silicone, on the other hand, can allow for multiple casts. The number of "pulls" one can get from a silicone mold depends on the casting method and medium involved, as the life of the mold is dependent on these two factors.
FRP (fiberglass) is used for all backups on our rubber molds. A mold can be only FRP as well. This type of mold is high production allowing for the most casts. However, it is best suited to basic forms with no undercuts, not intricate, highly detailed sculpture meant for rubber molds.