|Melbourne Museum of Printing||
Rubber Stamps and Matrices
The printer would use the same typesetting process as for printing, but then mould the types into a soft material instead of printing from them.
The soft material was then hardened and became a matrix from which one or more stamps could be moulded.
The matrix was filled with soft rubber (latex) which after curing (hardening) would take the shape of the original type. The rubber stamp was then glued onto a handle.
Many rubber stamps are still made this way, but the majority are made these days by processes which eliminate the type.
The Museum has a great collection of stamps, their intermediate stages and the things required to make them. And we use it occasionally to make stamps for ourselves or our visitors.