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PMC Silver Clay
There are currently 3 versions of PMC brand fine silver clay, 2 types of fine silver paste, 2 types of fine silver syringe, and a fine silver paper. Each type of clay and clay product handles slightly differently and has it's own unique working properties. By knowing the properties of each clay product, we can make smart choices about what clay to use for a project and take advantage of the unique characteristics of each material.

The PMC Forms: Lump, Slip & Paper
The basic clay material is called "lump form". It comes in a sealed foil packet and is ready to use. Lump form is used to roll slabs, snakes and to mold or sculpt objects. Lump form can be thinned with water and used as a paste.

Slip (or Paste) form comes in a jar or loaded in a syringe. The paste form is used like glue to paste wet or dry PMC objects in place, as a media for slip casting, for painting onto an object for a hollow form, and decoration. The syringe is used to extrude wire for decorating, setting stones, filling cracks, etc.

Paper form is a very thin sheet of clay that can be used to make bezels for objects to be set before or after firing, used for ring shanks, folded like oragami, shapes can be cut out with punches and applied as decoration. It can also be laminated with water to make it thicker.

Lump Form - PMC Standard
This product is 70% fine silver and 30% binder by weight. PMC Standard shrinks about 28% of its original size during sintering. The 2% difference between how much silver the clay contains and how much it shrinks is how much airspace is left throughout a piece after sintering. Objects made from this version are somewhat brittle. PMC Standard can withstand mild distortion such as dapping. It can be dapped (domed) slightly before it gives way to stress and begins to show cracking. It does not lend itself to bending.
Uses This form is excellent for highlighting details and texture. The shrink factor can be used as a design device to scale down larger forms. This version can be used to craft any type of item, but is not recommended for making rings. This version does not have the strength to hold up to the abuse that rings are subjected to and break easily. I avoid soldering PMC Standard. If you do solder this version, the area to be soldered must be burnished well. Be aware that it requires a huge amount of solder, about 4 times the normal amount, and you need to remove the flame the moment the solder starts to flow, leaving a lump of what I call solder slobber. Consider using a cold connection or embed and re-fire with other forms of PMC to incorporate it into a design.
Workability PMC Original stays moist longer than the other formulations, which gives a longer working time, but be sure to keep any unused portions tightly sealed from air because all metal clay (except paper form) dries very quickly when exposed to air.
Embedded Objects Any object that can withstand the firing temperatures and times of PMC Standard can be embedded and fired in place. Some natural gemstones, lab gems, cubic zirconia and porcelain can be used.
Firing Options
Temperature Hold Time
Kiln 1650F 2 hours
Torch Not Recommended 2 hours

Lump Form - PMC+
This product is 85% fine silver and 15% binder by weight. This variety shrinks 12-15% during firing. The metal particles in this version are smaller than those in PMC Original, which allows higher metal content and therefore less shrinkage. The firing times have been shortened dramatically from 2 hours to a minimum of 10 minutes.
Uses This form sinters more solidly than the original version and results in a stronger final product. This version can be used to craft any type of item, but we caution it's use for rings since it is not as strong as PMC3. It must be burnished well before soldering and uses surprisingly more solder than sterling silver.
Workability PMC+ dries more quickly than PMC Standard, so care must be taken to quickly remove and save scraps. Unused clay should be kept tightly sealed when not in use.
Embedded Objects Any object that can withstand the firing temperatures and times of PMC+ can be embedded and fired in place. Some natural gemstones, lab gems and cubic zirconia's can be used, as well as porcelain.
Firing Options
Temperature Hold Time
Kiln 1650F
1650F
1560F
1470F		 2 hours (optimum)
10 min
20 min
30 min
Torch Red Glow 5 min

Lump Form - PMC 3
This product is 85% fine silver and 15% binder by weight. This variety shrinks 12-15% during firing. The metal particles in this version are smaller than those in PMC Standard and PMC+, which allows higher metal content and therefore less shrinkage. The firing times can be as little as 10 minutes.
Uses This form sinters more solidly than the original version and results in a stronger final product. This version can be used to craft any type of item, and it is especially recommend for rings. When fired at the highest temperature (1650F), it produces the strongest final product. It must be burnished well before soldering and uses surprisingly more solder than sheet or wire forms of sterling silver.
Workability PMC3 dries more quickly than PMC Standard, so care must be taken to quickly remove and save scraps. Unused clay should be kept tightly sealed so that no air can contact it.
Embedded Objects Any object that can withstand the firing temperatures and times of PMC3 can be embedded and fired in place. Some natural gemstones, lab gems and cubic zirconia's can be used, as well as dichroic glass and porcelain. Findings and some types of glass can also be embedded when fired at the lowest temperature.
Firing Options
Temperature Hold Time
Kiln 1650F
1650F
1560F
1470F
1290F
1200F
1110F		 2 hours (optimum)
10 min
10 min
10 min
10 min
20 min
45 min
Torch Red Glow 2 min

Syringe Form
PMC+ and PMC3 are both available in syringe form. The clay has been loaded into a special syringe for extruding.
Uses This form is excellent for decorating objects and setting stones.
Workability Easy to use syringe, keep capped and in an airtight container when not in use.
Embedded Objects Follow the guidelines for embedded objects in the PMC+ or PMC3 lump version you are using.
Firing Options Fire at the same temperatures as for the lump form of the same PMC version.

Paste Form
PMC+ and PMC3 are both available in paste form. Paste comes in a jar.
Uses This form is used to decorate, attach parts and fill cavities, and can be painted onto objects.
Workability Paste is thick but is easily applied with a paint brush or pallet knife. Keep tightly closed when not in use.
Embedded Objects Follow the guidelines for embedded objects in the PMC+ or PMC3 lump version you are using.
Firing Options Fire at the same temperatures as for the lump form of the same PMC version.

Paper Form
PMC+ is available in a thin sheet measuring either 3x12cm or 6x6cm.
Uses This form can be cut with punches or scissors and applied as decorations to objects. Use for making bezels, folded or draped forms and ring shanks.
Workability PMC+ paper dries very slowly. It's exceptionally thin and can be laminated to make thicker sheets by applying a mist of water (very fine!) to the paper and folding in half or placing another sheet on top.
Embedded Objects Any object that can withstand the firing temperatures and times of PMC+ can be embedded and fired in place. Some natural gemstones, lab gems and cubic zirconia's can be used, as well as porcelain.
Firing Options Fire at the same temperatures as for PMC+ Lump.