Design Nomenclature / Physical Model Making
Pattern
Also called master pattern, plug, casting pattern
The object a mould is made from. It carries every surface the casting will have, plus the allowances the casting will not: draft so it releases, and extra size to cover shrinkage. A pattern is tooling, not a deliverable — it can be crude everywhere it does not touch the mould.
Not to be confused with
- MasterThe finished original a mould is taken from when the goal is copies of that exact object — usually the appearance model itself, surfaced and painted before moulding. Where a pattern is built in order to be moulded, a master is built to be looked at, and gets moulded because it came out well.
- MoldThe negative that gives cast or formed material its shape. One-part block moulds suit simple forms with a flat back; two-part moulds split along a parting line; glove moulds are thin silicone skins backed by a rigid mother mould, used where a solid block of rubber would cost more than the job is worth.