Design Nomenclature / Physical Model Making
RTV silicone
Also called RTV, tin cure silicone, condensation cure, platinum cure, addition cure, room temperature vulcanising
Two-part rubber that cures at room temperature into a flexible mould. Tin-cure is cheap and forgiving, shrinks slightly, and slowly dies on the shelf. Platinum-cure is dimensionally stable and inhibits — sulphur clay, latex gloves and some tapes leave it permanently tacky, with no warning, no smell, and no fix but starting over.
In practice
Everyone says "RTV" and means whichever bucket is open. Ask tin or platinum before you put a plasticine master in it — the answer decides whether the day exists.