Casting Process. These letters are made of metal, but they
can be used as master patterns to make many wax copies.
The process is to spray the metal letter with mold release, put in into a small box and cover it with
liquid silicone rubber (RTV). When the RTV cures it is slit open and the metal letter is removed. The
resulting cavity creates a mold for making a wax copy.
If you are making a lot of copies (say more than 20 or so) you can also use heat-vulcanizing rubber
in place of the RTV. The solid rubber mold will make hundreds of wax copies.