ABOUT PMC PRECIOUS METAL CLAY PRODUCTS
PMC or PRECIOUS METAL CLAY was developed in the early 1990s in Japan by metallurgist Masaki Morikawa. The PMC material consists of microscopic particles of pure silver or fine gold powder and a water-soluble, non-toxic, organic binder that burns off during firing. Success was first achieved with gold and later duplicated with silver. The PMC brand includes the following products:
The original formula of PMC, now called "standard": fired at 900 °C for 2 hours, shrinks by 30% during firing.
PMC+ & PMCflex: fired at 900 °C for 10 minutes or 800 °C for 30 minutes; shrinks approx 15%, due to a particle size reduction. PMC+ is also available in sheet form which can be worked like paper; for example, for origami.
PMC3: fired at 700 °C for 45 minutes or 900 °C for 10 minutes; shrinks by approx 10%. It can also be fired using a butane torch by heating it to orange heat for at least 10 minutes. It has a longer working life than the older formulations. It is also available in slip and paste forms which can be painted onto the surface of an object to be used as a mould.
Aura 22: a 22 k gilding material, a gold paste intended to be painted onto the surface of silver PMC pieces, or ready-made silver objects.
PMC Pro: a stroner product which is 0.900 silver, hence it cannot be hallmarked as sterling silver. It requires kiln firing embedded in activated carbon for 1 hour at 760 °C.
PMC Sterling: is fired at 815 °C and shrinks by 10-15%. Because of the copper content in this formula, firing is a two-step kin process; step one is an open-shelf kiln firing and step two requires a kiln firing with activated carbon media.