What is Polymer Clay?
Polymer clay is a man-made clay that uses PVC as its base. What makes Polymer clay so wonderful to me is the infinite ways that it can be used. It can be molded, sculpted, and extruded. The surface can be stamped, textured, embellished with powders, paints, or metallic leafs. Once baked it can be carved, sawn, cut, drilled, glued, painted, sanded, and buffed. It is compatible with – and often bonds to – objects and other materials that can withstand the low baking temperature required to cure the clay. It is available in a wide variety of colors that are mixable to produce an infinite palette. It can be made to imitate other materials, such as leather, gemstones, glass, stone, or wood. Perhaps the most amazing property of PC is its ability to stretch, reduce, and retain the color and proportion of assembled shapes – called “canes”.
There are many brands out there to work with. I’ve used them all over the years but prefer Premo and Souffle which are both made by Polyform Products. I particularly like Souffle when working with the cutters. It is durable and has a suede like feeling that seems to give a slightly cleaner cut. I have also done testing with Cernit, Fimo
Professional, and Kato Polyclay. They are all excellent products and if you are already experienced with a particular brand it will work fine with the cutters. No need to go out and buy more clay. I would not suggest Sculpey III or non-branded clays from the Big Box stores. They are made for kids and the quality of the finished products is not very good.
You needn’t spend a fortune to get started with polymer clay. Tools can be stolen from your kitchen, someone’s workshop, and picked up at garage sales (a great place to find the manual pasta machines). Tools used with polymer clay should NEVER come in contact with food again.
The Must Haves:
Work Surface – a large, smooth ceramic tile or smooth glass cutting board is best. Do not work on, or store, raw polymer clay on unprotected wooden furniture. The chemicals in polymer clay can dissolve the finish. Paper is not enough protection between your clay and wood furniture. The plasticizers will leach through the paper very quickly.
Cutting Tools – an Exacto knife, or scalpel, plus a polymer clay blade. This is a very thin long blade and is particularly helpful when working with clay and the cutters. In a pinch you can use
a scraper blade that is made for scraping wall paper from walls and can be found at most hardware and home improvement stores.
Conditioning and Sheeting Clay – Polymer clay needs to be ‘conditioned’ before you work with it. You can use your hands by squeezing and twisting the clay to soften it and redistribute the plasticizers that have settled in the package. You can also use a lucite, plastic, or metal rolling pin. However, the best way to condition the use a manual pasta machine or a made-for-polymer clay conditioning machine. Soften and flatten the clay before putting it though the machine at the thickest setting so you don’t strip the gears. Continue by folding and rolling the clay through the various settings until the clay is soft, supple, and has a slight sheen. When cutting the clay with a cutting machine it is very important to have a consistently even sheet of clay and to know the thickness of that sheet. The best way to measure the thickness is with a conditioning machine.
Curing the Clay
One of the great things about polymer clay is that it cures in a normal oven and does not require a kiln. It is VERY important that you follow package directions about baking temperatures. You MUST use an oven thermometer to test the actual temperature of the oven you’re using. Polymer Clay will BURN above 325 degrees and can emit noxious fumes. I suggest that you calibrate your in the following way:
- Set the oven at the temperature recommended on the package.
- Place the oven thermometer in the oven.
- Check the thermometer every 10 minutes and note the temperature. All ovens spike but in different degrees. You want to make sure that the oven does not reach more than 325 degrees, or less than the package’s directions, for any significant length of time.
The length of baking depends on the thickness of the clay. Minimum time for complete curing is 20 minutes. Polymer can be baked for longer periods as long as the temperature does not change significantly. It can also withstand multiple bakings. I bake pretty much everything for 40 – 50 mins.
If you use your kitchen oven you should bake your clay inside of a baking bag, a covered casserole, or two aluminum foil baking pans clamped together which are only used for baking clay.
NEVER use a microwave to warm or bake. Small toaster ovens are not a good choice because the temperature spikes too much. A tabletop convection oven/toaster is ideal.
Polymer clay should be stored in a cool place away from heat and sunlight. Storing near a window that gets a lot of sun is a no-no. Also, don’t leave it sitting in the car in warm weather as it starts to cure when exposed to 90 degrees for a period of time. Polymer clay reacts with most clear plastics but stores well in frosted plastic like Plano fishing tackle organizers and rolling plastic drawers found at office supply and discount stores. It can also be stored in ziplock plastic bags and clear plastic wrap.
More Curing tips:
- Parchment paper or card stock should be used to line metal or glass baking surfaces because both surfaces can cause shiny spots where the clay comes in contacts
- There are several ways to support rounded surfaces (beads, pens, sculptures) from developing flat spots while baking:
- Place on a thick layer of cornstarch in an oven safe container
- Create a bed of polyester fiberfill to rest objects on
- Fold a piece of card stock into accordion pleats and place beads in the pleats to limit flat spots.
- Support with crumpled aluminum foil covered with paper towel or fiberfill.
I’ve only scratched the surface about working with polymer clay. The following links and books will help you find you way with issues I haven’t touched on here.
POLYMER CLAY RESOURCES
Craftcast – www.craftcast.com – Allison Lee’s great site for live webinars, podcasts, and video tutorials
The Blue Bottle Tree – www.TheBlueBottleTree.com – Ginger Davis Allman has compiled a super site that includes tutorials, comparisons of products, and general information.
Polymer Clay Tutor – www.beadsandbeading.com – Cindy Lietz runs this blog site and there is a lot of good information for beginners there.
CraftEdu – www.craftedu.com – is a project from Donna Kato that offers online classes in lots of mediums, but especially in polymer clay. Also includes a lot of free tutorials.
Polymer Clay Express – www.polymerclayexpress.com – They carry any and everything that relates to polymer clay. Great to deal with and their prices are very good, although freight can be high on clay.
There are a ton of books that focus on all types of polymer clay techniques and projects. And new ones come out almost every month. If you can only buy one book each of these cover a lot of information.