Art Clay Copper

Characteristics of Art Clay Copper

  • You can make  a copper object or jewelry from modeling clay.
  • It is water based clay.
  • Fired piece contains more than 99.5% pure copper .  The percentage of copper in the clay (before firing ) is 90%.
  • The shrinkage after firing is about 10% in length.

Clay Type

  • Available in  50 g package. (25g is packed separately inside)
  • Recommended to use separate tools for Art Clay Silver Series, those clays may be contaminated each other.
  • After the firing, the layer of the piece will oxidize, so remove it with pickling solution to obtain pure copper color.
  • Once opening the package, clay naturally get oxidized, so take necessary amount of clay and wrap in several layers of plastic wrap tightly and them place in a zip-up type plastic bag, or an air tight container

How to make paste form from Clay Type

Apply a small amount of water to some soft clay or ground powder of dry clay, and blend well while crushing in any hard pieces. Use this paste for filling up any cracks in the dried clay of your piece, and for joining clay parts.

New Mokume Gane technique

  • This is totally new application designed for Art Clay Silver and Copper based on traditional Japanese metalsmith techniques developed back in the 1600s in Japan for sword fittings.
  • Mokume means Wood pattern. Gane is metal alloy made from mixed-metal laminate with distinctive layered patterns. To achieve high quality Mokume-Gane by traditional way, it requires adequate experiences, tremendous time for making process, and many special equipments.  So, the technique has been inherited by only limited craftsperson, but its beauty applied into today's craft work and jewelry in Japan and overseas with high reputation.

Condition for Drying and Firing


Reference guide for an object up to 1mm thick and 5g. If your work is larger, more drying time will be needed. There are several ways to dry your work as listed below.

  • Hair dryer: At least 10 minutes with a 1200w hair dryer. Place the dryer within 5-10cm/3inches from the piece.
  • Cooking plate: At least 10 minutes at 150℃/302°F
  • Kiln: At least 10 minutes at 150℃/302°F
  • Natural / air dry: At least  24 hours at room temperature.

*Do not apply the heat over 250℃/482F, otherwise the binder burns away and shape of the piece will change.

How to tell when the piece is dry enough

Place the piece on a sheet of stainless steel, glass or plastic and after 10~20 seconds pick up the piece. If there is no croud of water vapor, it is dry. (It is easy to check the vapor cloud on black stainless, glass or plastic).

*the image left, there is still water vapor on the stainless scraper, so it is not dried completely yet.

Firing & Pickling


Kiln firing is recommended

Place the piece into a kiln at 970℃/ 1778°F, and hold at this temperature for 30 minutes to fire.

*After firing, quench is needed to get rid of oxidized layer, please check the instruction below.

<Caution for firing>

  • Please wear safety glasses when firing, always use the proper equipment and follow all safety precautions.
  • Work in a well ventilated area when firing the piece.
  • The fired piece is extremely hot when taken out from the kiln.
  • Large volume pieces of more than 15 mm thickenss may crack if placed directly into a high temperature kiln, so  fire such larger pieces from a cool kiln.

<Warning for firing>

If a hot fired piece is left in the air right after firing, the oxidized layer on the surface will fracture and at times small pieces can fly into the air. For your safety in such cases, immediately place a fiber cloth over pieces. You can also leave the fired piece in the kiln to cool, however clean up the oxidized layer outside of kiln.

Quench & Pickling

After Firing, take out the piece with tweezers or tongs from the kiln, and quench immediately with water, so that most of the oxidized layer will peel off .

Place the fired piece into a solution made with pickling compound to take away any oxidized layers on the surface. For any oxidized layers around detailed design areas, please use a polishing point with an electric rotary tool.

*For use and proper disposal of the pickling solution, please be environmentally responsible and follow the instructions included with this product carefully.


After firing, the piece is pure copper. You can enjoy its beautiful metal luster by polishing with a metal brush, burnisher, polishing points and a tumbler.


  • This product may crack and burst during firing if insufficiently dry.
  • Oxygen is consumed during firing and smoke and gas emissions may result. Please fire in a well ventilated area.
  • Do not place just-fired pieces on any flammable surfaces or combustible materials as the piece will be extremely hot and could cause a fire.


  • Take precautions against burns from the heated clay when drying, firing, and after firing.
  • Keep out of the reach of children. If the product comes into contact with eyes or mouth, please rinse thoroughly with running water. If problems persist, please see a doctor.
  • Be aware that some people are allergic to Copper. The level of reaction is different according to the individual, from light to severe. If you do have an allergy against copper and work with and/or wear copper accessories made from the product directly on the body, some kind of allergic reaction may occur. If in doubt, please seek medical advice from a qualified medical practitioner before use.