Q: Is the rubber mold used to make multiple wax positives for lost wax
casting or is a wax positive used to make the rubber mold?
A: It can be done either way. Usually the (second generation) wax comes
from a rubber mold, created when sheets of rubber are vulcanized (melted
together under pressure) around a piece of jewelry. The mold is then cut
apart to remove the model and leave a cavity to be filled by injected wax.
In addition, RTV (Room temperature vulcanizing) molds can be made around
wax models because they cure at room temperature.
Each has its +'s and -'s.