What is plaster modelling and plaster casting?

Question

I have an art assignment about Claes Oldenburg and we need to find out what plaster modelling is and how pop artists used plaster casting to enlarge objects. Any help?

Answer 1

Plaster modeling is normally taking a chunk of plaster and carving it (like one does marble or wood) to make an art object. Since plaster can be added to, it is possible to make a model, make a copy (see below) then add some plaster back in and carve that.
Because of what Claes makes, it is likely that this is what he makes - a maquette http://www.modernsculpture.com/glossary.htm that allows himself, his clients, and his construction people to see what is to be built much larger. It is not used to enlarge objects directly, other processes do that.
Plaster casting normally involves making a mold, which may be plaster, latex, rubber, etc., from a model, which may be wood, plaster, clay, or other artists materials as well as human flesh and other natural objects. The mold is used to make exact sized copies. In addition, plaster molds are used to make bronze castings where the outer surface of a clay is molded then a wax copy is made which will be melted away to make the hole into which the bronze is poured.