Body Casting

This is a complicated subject, and the results depend on a lot of variables. If live models are involved, there are also safety issues. Obviously, all I can do here is give you a few pointers, not a complete class on the subject.

Plaster bandage masks can be done quickly, but the results are not great, especially if you are interested in capturing detail. (Don't tell George Segal I said so.) If you are interested, there are instructions for this process posted at the Far-out Fabrics site at http://www.mendels.com. Dental alginate is the best negative material I've found for this sort of thing; it will capture fine detail, but it isn't strong. Prent sells a slow-set version which gives a bit more working time. The alginate will sometimes tear when one is unmolding the plaster positive, especially in deep or trapped undercuts. Count on one good positive only per mold. This can of course be remolded with a rubber compound, if multiple casts are required. Casting plaster works as a postive casting material in alginate or rubber molds, as do other gypsum cement products which are stronger. It is very difficult to make a cast of one's own face- I've made molds of all kinds of things, but have not attempted this. Even making one of another person's is tricky. I would definitely not recommend this as a first project in life-casting. If you really want your life-mask made, have an experienced person do it for you. If you want to mold sombody else's face, work up to it slowly-start with inanimate objects, then a hand or foot; only when you have mastered the technique should you try a living face. Although some sculptors have made molds by putting plaster directly on a person's skin , this is a dangerous thing to do; burns can result from the exothermic reaction of the plaster's setting. I can only imagine the scene when you realize that this hard and heavy plaster thing that is covering your face won't come off, and it is getting hotter...

In the recommended process, the mold is made from dental alginate, which is available in warm water and cold water versions. If you don't like goosebumps on your castings, the warmwater kind is preferable. The mold material is a powder which is mixed with water and stirred into a paste, which is applied as quickly as possible- it sets within three to five minutes. The material when set is a flexible gel which peels off skin readily - no release is necessary for skin that is not densely haired. (It should be masked off from head hair.) I have seen fiberglass casts with all the model's body hairs in place- the plaster pulled them out when the mold was removed (ouch!); the fiberglass positive then pulled them out of the plaster. The mold may need a supporting shell to faithfully retain the form of the part being molded. These may be improvised from plastic containers or built up with plaster and cloth, which takes longer. When the mold is taken off the model, plaster is poured in, and left to set. If a permanent mold is needed, then this first plaster positive is used for a master in the RTV rubber moldmaking process. Subsequent castings from the alginate mold will be progressively more degraded, due to cuts, tears, and general erosion. The alginate -usually the cold-water version- may be purchased at dental supply houses, or one can obtain it from sculptor's supply places. A place in Vermont that specialises in life-casting supplies is Pink House Studios: 35 Bank St. St Albans, Vermont. (802)524-7191. Mark Prent, the owner, specialises in life-casting techniques, carries a line of supplies, and also sells instructional materials including video tapes.