Polymer Clay and Metal Clay
What is Polymer Clay?
Polymer clay is a light-weight substance made from a PVC (polyvinyl chloride) resin and a liquid plasticizer, making it a plastigel. Like metal clay, it is stable at rest and becomes ‘fluid’ while conditioned or shaped. Most polymer clay formulas do not air dry, unlike metal clay, which must remain moist to retain plasticity. Polymer clay remains stable even when heated, which makes it an excellent choice for making jewelry and crafts.
Brands of polymer clay include but are not limited to: Premo, Souffle, Fimo, Cernit, Pardo, and PVClay. Many craft stores also have their own store-branded clays that behave similarly. Bake and Bend by Sculpey is good for creating molds, including those that would be used with metal clay. There is also liquid polymer clay which can be used in many ways. It can attach baked polymer clay elements together, secure findings, condition dry clay, allow for the inclusion of non-polymer clay elements such as foils, it can be used as a surface design element, be tinted to be used as a paint, and can serve as a vehicle for image transfers.
Benefits
Polymer clay comes in multiple colors, which mix true. It can also be used with many other substances to create wonderful surface effects.
Polymer clay is reasonably strong when properly baked and cared for. Setting it in fired metal clay so the metal can protect it from damage also helps.
Possibly, the best part of polymer clay is that it is affordable, and setting up a polymer studio requires a relatively low cost investment. It is not recommended to use all of the same equipment as metal clay due to the risk of contamination, but non-porous tools, such as cutters, can be used between metal clay and polymer clay provided they are cleaned between mediums. A dedicated toaster oven is used instead of a kiln and a pasta machine, also dedicated for non-food use is used to condition the polymer clay, roll it to consistent thicknesses, and even pattern the clay with certain texture plates. These two tools will be the largest expenditures in setting up a studio.
There are many reasons why metal clay and polymer clay are complementary. Polymer clay is light and metal clay is heavy. Polymer clay has vibrant colors and metal clay does not. One makes the other stand out. Metal clay gives polymer clay some importance and polymer can add some playfulness to metal clay.
Uses
Polymer clay has many uses. For the metal clay artist, it can be used to make molds, forms, stamping and texture plates, props, and design elements. It can be used to create prototypes, or masters that can be molded in another material to be used with metal clay. It can be carved, used for image transfers, cane-making, mica-shift, mokume gane, creating beads, or creating faux materials such as simulated beach glass, wood, and semi-precious stones.Polymer Clay can also be used with a myriad of surface treatments, including but not limited to, stencils, glitter, crackle paints and glazes, acrylic paint, and alcohol inks. It can be textured with photopolymer plates, molds, stamps, or a computerized cutter using SVG files.
Jewelry Making and Beyond
Carved Polymer clay bangles, Artist: Celie Fago
Warnings
Although it can be quite sturdy, polymer clay is not as strong as metal clay. Like metal clay, it can be baked longer to strengthen it, but should not be baked hotter. Polymer clay can burn if overheated and will release dangerous fumes and particulates.
It is important to have good ventilation when working with polymer clay. If it burns, it can produce hydrogen chloride, which can irritate the nose, mouth, and airways. Some early versions of polymer clay contained phthalates but, when it became clear that they were a health risk, manufacturers started removing them from polymer clay.
Of note: Â Polymer clays that contained phthalates made it easier to do the Tear Away technique, which can create texture plates with relatively deep undercuts. In the Tear Away technique, a laser printer is used to print a black-and-white image onto paper. The paper is then bonded with heat to a sheet of polymer clay. The toner from the printer adheres to the clay because of the reaction between the clay and the plasticizers in the toner. Once the image has bonded with the clay, the paper is torn/pulled away, and the toner, which clings to the clay, removes the polymer where the image is. This creates two textured images, a positive and a negative, that can both be used with metal clay as texture plates. The polymer clay that has bonded to the paper makes a low-relief sheet, whereas the clay side provides a shallow texture plate.
Polymer Tear Away Inlay, Artist: Celie Fago
Polymer Paper Locket, Artist: Celie Fago
It is still possible to do the Tear Away technique with today’s polymer clays, but the removal of the phthalates makes it more difficult to get deep undercuts when making the texture sheets. It is possible to find older clay that has phthalates in usable condition (gold-colored clay seems to be the most successful with this technique).
Uncured/unbaked polymer clay can react with other plastics, surfaces such as lacquers on furniture, and certain resins, including those used for fingernails and nail polish. It is important not to leave uncured polymer clay in contact with other materials due to the possibility of a reaction. Polymer clay that has begun to react with resins or plastics, causing the polymer clay to melt or become gooey, will need to be disposed of.
Connections
It is ideal to create a mechanical connection between polymer clay elements and sintered metal clay unless a polymer clay safe glue or resin is to be used. When attaching polymer to metal clay pieces there are several design considerations. The most important one is how and where the polymer will attach to create a secure bond. If using glue or resin, you may want to sand the area, where pieces will attach, to create ‘tooth’ for gripping.
Unlike metal clay, shrinkage cannot be used to secure polymer clay to a metal element as the shrinkage rate is only about 1%.
The most common forms of attachment between polymer clay and metal clay are as follows:
1. Glue or resin.
Although a mechanical connection is a more secure way to attach polymer to metal clay, it is possible to use glue or resin to accomplish this, especially when a piece is less likely to be stressed – like these earrings.
2. Attachment through a hole.
This is most effective when one piece of polymer sticks through the hole in the metal clay element. For a very secure connection, It is advisable to attach polymer clay to itself by putting it through the hole so the clay is bigger on each side of the hole and can’t come out. This allows for a double-sided element if desired. This applies to holes of any size where there is more space on one side of the hole than the other. This is sometimes referred to as a rivet.
Polymer Inlay, Artist: Celie Fago
3. A bezel attachment
This is where a bezel holds the polymer inside a space. Undercuts in the walls of the bezel can help secure the polymer clay into the space in the metal clay element.
4. A tube liner
In this technique, a sintered metal clay tube is covered in whole or in part with polymer clay to create a bead or pendant.5. An Embeddable
A wire or tube is attached to a piece covered by polymer clay so the embeddable cannot pull out of the clay. Fancy bails, connectors, clasps, or other functional elements can be made from sintered metal clay to provide durability that polymer clay does not have to areas of a piece that will be high wear or high stress.
6. Cold connections
These can include metal rivets made of wire or tubing. These can be passed through the polymer clay to attach to elements together or add small items.
7. Design component
Creating one or multiple holes with bars or rings through which polymer clay can pass. These can connect to two sides of a metal clay piece and polymer clay can pass through them. This clay, which can sometimes be made of scrap clay, can then attach to clay above it when heated. This will secure the piece with a mechanical connection. For longer pieces, multiple rings or bars are helpful.
Additional Resources
There are many ways to learn how to use polymer clay. These include but are not limited to Pinterest, Facebook Groups, books, guilds, tutorials, and classes at craft shows.
Likewise, there are many places to purchase tools to use with polymer clay, and tools from other mediums, such as leather working, resin casting, and ceramics/sculpture can be used. Many tools are the same for both polymer clay and metal clay, but cross-contamination can ruin a piece, so keep porous tools separated and have a vigorous cleaning process for tools that will be shared.
Recommended Reading
Perfectly Paired: Designing Jewelry with Polymer and Metal Clays. By Patricia Kimle. Kalmbach Books. Waukesha, WI. Published 2010.
‘Warm Connections: Combining Polymer and Metal Clay (Parts 1 and 2)’. By Patrik Kusek, moderated by Alison Lee. www.craftcast.com. 2008.
Can you picture this amazing type of mixed-media marriage in your future?
Author: Vanessa Weber, Editors: Julia Rai, Loretta Hackman