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About Polymer Clays
From left to right: bulk white Sculpey, Super Sculpey and Sculpey III Note that there are three different kinds of Sculpey. There is bulk white Sculpey, a white, doughy polymer clay sold in two-pound boxes, and there is Super Sculpey, a translucent pink, waxy polymer clay sold in 1-pound boxes. Super Sculpey is twice as expensive as regular Sculpey, but it's pretty much twice as easy to smooth and much less brittle once it's baked. Hereafter, if you see me use the term "Sculpey" you should consider that to be Super Sculpey unless otherwise noted. The other brand of polyclay I use is called Sculpey III (sold in 3-ounce packages similar to Fimo). It's essentially Super Sculpey that has been tinted. Other polymer clays include Promat (also by Polyform) and Fimo (manufactured by Eberhard Faber GmbH, a German company), both sold in 3-ounce packages, but since I don't use these products, I'll leave them to you to experiment with. I sculpt with a mixture of Super Sculpey and Sculpey III--one 3 oz. package of Sculpey III with one one-pound brick of Super Sculpey. I used to mix Fimo with my Sculpey, and here's why I switched. The first problem I was having with the Fimo/Super Sculpey mix was that when it came to smoothing it out, it often "crumbed up" due to the stiffness of the Fimo. The Sculpey III mixture smooths really well. Anyone who has used Super Sculpey knows that it does get steadily firmer when it's exposed to air, i.e. after you've placed it on the armature and begun to sculpt. For some reason, Super Sculpey is sold in non-airtight boxes, so check yours for softness when you get it at the store. If you can't find soft Super Sculpey, there is a method for making it softer. I find that if my Super Sculpey/Sculpey III mixture is too firm when I start sculpting, it can get really stiff and unmanageable as I continue to sculpt. I had some problems with the baby raptor because of this. If you start with a Sculpey mix that is a little on the soft side, you'll find that by the time you get well into the sculpting process it will have firmed up to a nice working consistency. Sculpey III comes in a variety of colors, and you can choose a color you like to work with. I prefer a gray Sculpey blend, as it creates a nice neutral color when blended with Sculpey. Since Polyform doesn't make gray Sculpey III any more, I just combine a 3-ounce package of black Sculpey III with a 3-ounce package of white Sculpey III and add this to a 1-pound box of Super Sculpey. The main reason I use Sculpey III is that Sculpey in its normal state is slightly translucent, which can cause problems when sculpting details. Mixing it with the colored clay eliminates the translucence, and makes sculpting easier. Note: from here on out, all references to Sculpey refer to Super Sculpey, and not the bulk white stuff. I don't use the latter at all. Purchasing Polymer Clays As noted above, Sculpey does stiffen up when exposed to air for a period of time. The boxes it's sold in are not airtight, so you should open the box and check its consistency with your fingers before you buy it. Sculpey that has been sitting on a shelf forever will be hard and stiff, whereas newer Sculpey will have a soft, pliable consistency. Generally, the softer the Sculpey, the better it will perform for you, so check your clay before you buy it. Also keep in mind that your sculpture will be sitting out in the air for the duration of time that you're working on it, so if the Sculpey is a little too soft for your taste in the store, it'll stiffen up while you're sculpting with it (unless you work a lot faster than me). Sculpey III is sold in airtight packages, and is much more consistent in its softness. Storing Polymer Clays Store your Sculpey in an airtight container (a Ziplock bag works fine) in the refrigerator. I take my Sculpey out of the box, wrap it with some cling wrap and then put it into a Ziplock bag). Let the clay reach room temperature before you condition it prior to sculpting. Don't store Sculpey in polystyrene boxes, as it will melt the polystyrene. Similarly, don't place any raw clay on varnished or lacquered wood surfaces, as the solvents in the clay will damage the finish. Keep it away from most plastics too. Conditioning or Softening Your Clay It's very important, when using polymer clays, to "condition" them prior to sculpting. Conditioning is simply kneading and working the clay with your hands for a period of time. Conditioning your clay softens it and makes it stronger once it's baked. The rule of thumb to use when conditioning is to knead the clay for the length of time that it take two different colors of clay to become completely incorporated into a single color. This is another reason to mix colored Sculpey III with your Super Sculpey: you'll know your conditioning is finished once the mixture combines into a single, homogenous color. Sculpey comes out of the package in four slabs, so I cut the 3 ounce package of Sculpey III into four equal parts and mix one slab of Sculpey with one slab of Sculpey III. Simply knead the two clays together. Once the clay is a uniform color, it's ready. If your clay is stiff and hard, conditioning it can be very hard on your fingers, so you can remedy this and speed the conditioning process along by using an old pasta machine. I actually bought a new pasta machine for this purpose, and it paid for itself by reconditioning a bunch of older Sculpey that was too hard to knead with my fingers (I was ready to throw it out). Once I reconditioned the clay, it was as soft as the day it was manufactured, and I used it in a number of sculptures. Sometimes you can't find soft Sculpey at the store, so you have to buy the old, stiff clay, and reconditioning it with a pasta machine will make it like new.
My hand-cranked pasta machine The key to this process is a liquid known as Sculpey Dilutent. It's the clear liquid component of Sculpey, and it's sold wherever Sculpey is sold in little one-ounce bottles. You can use it to restore Sculpey to a softer, more pliable state.
Sculpey dilutent, a great product for softening stiff Sculpey To condition or recondition your clay with a pasta machine, set the machine to its "thickest" setting (leaving the widest gap possible between the metal rollers). Then simply roll the clay through it once to flatten the clay out. If the clay is really stiff, it will come out in ragged tatters--never fear, it will get better. Add some drops of Sculpey dilutent to the clay strip, rub it in with your fingers, and then fold the clay over and run it through again to blend the liquid with the clay. You will need to refold the clay and run it through a few more times to really soften it up.Continue to roll the clay through, adding more drops of dilutent as needed to get the clay to the desired softness. When the clay comes out of the machine in a smooth, pliable ribbon, you've reached the right consistency. Note: Never use a pasta machine for making pasta (or any food items) again after using it with polymer clays! This is why I suggest using an old pasta machine. Caution: Polymer clay contains chemicals which are harmful if ingested. Always wash your hands after sculpting with polymer clay and if you use eating utensils for sculpting tools, do not use them for eating again afterward. Do not leave polymer clay where little children can get hold of it, and do not use baked polymer clay items as food or tobacco containers. Baking Polymer Clays There are a lot of theories about baking Sculpey. Most sculptors have their own ideas. The Sculpey package gives instructions for baking it in your home oven (never use a microwave). According to the instructions, you bake a sculpture at 275 degrees Fahrenheit for 15 minutes per each quarter inch of thickness. To avoid scorching my sculptures, I prefer to bake a lower temperature for a longer period of time. I bake a sculpture at about 200-225 degrees for 20-30 minutes per quarter inch of thickness, then let the sculpture cool in the oven and bake it a second time (same temperature and time). This gives good results, but you might want to experiment to determine your favored baking method. Don't bake polyclay at temperatures higher than 275 degrees Fahrenheit, however. If it's turning black around the edges, your temperature is too high. Baked Sculpey is still quite soft while hot, so don't touch it until it's had a chance to cool off, or you may cause cracking to occur. If cracks do form in your sculpture, they're usually easy to fix. Use gap-filling superglue (cyanoacrylate) to fill smaller cracks. Wipe excess glue from the sculpture with little "twists" of paper toweling. Larger cracks can be filled in with two-part epoxy putty. It's a good idea to feed a little superglue into large cracks before filling them with putty. Painting Your Piece You can paint your sculpture with just about any hobby paints. Acrylic paints work really well. I suggest priming it with light coats of lacquer-based automotive primer prior to painting. |
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medium I sculpt in is known as polymer clay. Polymer clay (also called
polyclay) is essentially tiny particles of polyvinyl chloride (PVC) suspended
in a petroleum distillate compound. Polymer claycan be baked in your home
oven, at which time the petroleum distillate evaporates and the PVC particles
fuse into a plastic-like compound. It's a terrific material used by many
sculptors and craftspeople nowadays. There are many different brands of
polymer clay, but the most commonly available is Sculpey, manufactured
by Polyform Products Company, Inc. This article was revised in October
of 2001.
