Masters and Mould-making for Resin Production

All moulds have a limited lifespan, but the way the master is made can make a big difference. When making a master for resin production, it pays to bear the following in mind:

  • Avoid very thin sections where possible
  • To prevent the mould rubber penetrating the master, ensure full adhesion between layers of material and components
  • Do not use absorbent materials such as wood, cloth, paper or cardboard
  • Make your master solid to avoid collapse under the vacuum that is used to make the mould bubble-free

Our expertise means we can assist you in the design of a master that will ensure a high quality product and a long mould life. We might recommend a multi-part kit or a mixed media approach - see our in-depth case study for more information.

Room Temperature Vulcanising (RTV) rubber moulds are the ones most commonly used for resin production.


  • Longer mould life in use
  • Cheaper
  • Very good reproduction of fine detail


  • Slower to produce as the rubber needs post-cure time to fully harden
  • Continue to cure causing shrinkage over time
  • Shorter storage life

Addition cure silicone rubber moulds used for short run resin production.


  • Faster cure time with no post-curing needed
  • Dimensionally stable with little or no shrinkage
  • Very good reproduction of fine detail
  • Longer storage life


  • More expensive
  • Decreased mould life due to styrene degradation caused by the resin