Ben Hom wrote
from a kit manufacturer's point of view - two masters will allow youBen, it was explained that for production, a styrene master is used
to create very hard rubber, high precision molds from which "master
clones" are made. These clones are then combined into production sets
from which RTV molds are made. Those are the molds used to make kits.
They are usually good for 30-40 uses each. A successful freight car
will sell 300 or more kits, so that's a lot of molds!