Strange India All Strange Things About India and world


An Overview of Basic Skills and Tools for Sculpting in Polymer Clay

I have many lenses here on Squidoo about sculpting in polymer clay but none that really give a good overview of what you need to get started. This lens is about the essential information you need to get started sculpting in polymer clay, then you can move on to my other lenses for more in details on specific sculpting topics.

What is Polymer Clay?

Polymer clay is a non-toxic man-made sculpting material which stays pliable until cured at relatively low temperatures, typically between 265 and 275°F (129-135°C).

There are a number of brands and specialty clays with different properties.

For more in depth information see the Wikipedia Polymer Clay article.

Major Brands

Polyform

  • Sculpey
  • Sculpey III
  • Super Sculpey (Original and Firm)
  • Premo! Sculpey
  • Translucent Liquid Sculpey
  • Sculpey Super Flex
  • Sculpey UltraLight
  • Sculpey Clay Softener

Eberhard-Faber

  • Fimo Soft
  • Fimo Classic
  • Doll (Puppen) Fimo
  • Fimo Liquid (Deko Gel)
  • Fimo Lacquer
  • Fimo Effects
  • Fimo Mix Quick

Donna Kato

  • Kato Polyclay
  • Kato Liquid Polyclay

Prosculpt

  • Prosculpt Clay
  • Prosculpt Smoothing Oil

Other Brands: Cernit, Pardo

Which Brand Should I Choose?

Most polymer clays are good for sculpting so it’s mostly a personal choice as to which one you use.

Clays that work well for sculpting include Super Sculpey, Super Sculpey Firm, Premo! Sculpey, Fimo Classic, Puppen Fimo, Prosculpt, and Kato Clay. Generally you can mix different colors and brands of polymer clay together to get custom mixes.

Clays that don’t work particularly well and should be avoided include: Original Sculpey, Sculpey III, and Fimo Soft are not durable enough for sculpture. Specialty clays like Granitex (which has a gritty rock-like texture) and the liquid clays are not for general sculpting but work well for certain effects.

Is Sculpting in Polymer Clay Different than Sculpting in Other Clays?

The modeling properties of polymer clay are similar to working in oil based plasticine clay. Polymer clays are a little more rubbery and less sticky than plasticine but otherwise you can generally sculpt in polymer clay like you would with oil based clays.

There are a few things with polymer clay that differ from other clays:

Smoothing – Unlike with natural clays polymer clay can’t be smoothed with water. Instead isopropyl (rubbing) alcohol at 90% or 70% solution, sculpey clay softener (also called diluent), acetone, or turpenoid can be used for smoothing. Acetone and turpenoid are both highly toxic chemicals so I don’t recommend using them but they do work. Always leave a sculpture to dry at least overnight after smoothing before curing the clay.

Leaching and softening – Sometimes polymer clay can be either too soft or too dry, both can be remedied.

If clay is too soft you can leach it, this is done by laying rolled sheets of polymer clay between plain white paper (colored or printed paper will transfer ink to the clay), stacking books or other heavy objects on top, and leaving it for several hours or overnight. The paper absorbs the excess plasticizers in the clay firming it up.

If clay is too dry you can mix a few drops of sculpey clay softener (diluent) or a small piece of fimo mix quick into the clay. This will soften the clay by adding more plasticizers.

Basic Polymer Clay Safety

Sculpting tools should be dedicated to clay work and should never be used for food afterwards. That includes rolling pins, baking sheets, and knives. I also recommend using a dedicated toaster oven and if you must use your kitchen oven (say for sculpts that don’t fit in the toaster oven) you should either clean it afterwards or enclose your sculpt in a roasting bag/aluminum foil.

Clean your oven thoroughly after baking polymer clay unless it is dedicated to polymer clay use or if clay was baked in a sealed container like a roasting bag.

Follow common sense when handling sharp or hot objects. Always wear safety glasses if using a powertool such as a dremel.

Pthalates

Polymer clays are certified non-toxic but there is some controversy over the presence of pthalates in polymer clay. The jury is still about on how harmful the pthalates used in polymer clay really are but they are in some polymer clays to make them more pliable. These chemicals can enter your skin while you are handling the raw clay (however no evidence exists that these chemicals can leach from cured clay into skin). If you are worried about it you should wear latex or nitrile gloves, barrier creams may also work.

Due to concerns about pthalates and new European Union regulations most polymer clays will be changing their formulas within the next couple years. Kato Clay will be the first rolling out the new formula in the US. Read more about it from Katherine Dewey.

Beginner’s Tool Set

My recommendations for a very basic tool set to start with. You can then build on this set either buying or making more tools as you go.

Work Surface

Polymer clay isn’t as messy as some clays but it can make a mess and it can damage wood furniture so you need a dedicated work surface for sculpting. Good options are:

Glass – This can be a plain sheet of glass (put masking tape on the edges if they’re sharp) or a glass cutting board. I even found an old round glass table top that was going to be thrown out that works great. One of the benefits of glass is that you can slip reference diagrams and photos under it.

Craft Mat – Self healing craft mats are typically sold for scrapbooking or quilting but they also make good surfaces for clay. They usually also have a measured grid that can be useful.

Cutting Tool

I recommend a good sharp craft knife such as those by x-acto. A dull knife will work but you won’t get good crisp edges.

Rolling Tool

This can be a rolling pin, acrylic roller, heavy drinking glass, or a pasta machine. Anything that works to roll out sheets of clay.

Simple Modeling Tools

You can get a basic set of 6 wooden sculpting tools at just about any art store. Get the wooden ones, they aren’t much more than the plastic sets and they work much better.

Loop Tools

Loop tools are for removing fine bits of clay from your sculpts. You can buy these at an art store or make them with dowels, music wire (like from guitar strings), and glue. See my Polymer Clay Sculpting Tools lens for more about making tools.

Needle Tool

Needle tools are exactly what they sound like, a needle-like metal spike on a wooden handle. They are useful for scribing lines and poking holes in clay. You can buy one from an art store or make one using a dowel and a heavy tapestry needle.

Storage

I use a small toolbox for my sculpting tools but a desk drawer, pencil box, shoe box, etc. all work well for keeping tools organized and in one place.

What is an Armature?

The armature is the skeleton of your sculpture. It’s an internal structure that gives added strength and support your sculpture to keep it from breaking and also reduces the amount of clay you need to use. Armatures can be made from a variety of materials such as wire, crumpled up aluminum foil, sculpting epoxy such as Aves ApoxieSculpt, Sculpey Ultralight clay, or a combination of materials.

Do I need an armature?

If you are doing any complex figure with thin extremities such as arms, legs, tails, etc. or a large figure you need an armature. The reason large figures need armatures is that any layer of polymer clay thicker than 1/2 inch is difficult to cure thoroughly and evenly so a large sculpture should be bulked out with some other material such as aluminum foil or epoxy.

The Basic Techniques of Sculpting in Clay

There are three general techniques for sculpting in clay which all other techniques fall under. These are my own terms.

Adding

This is adding clay to your sculpture. Taking little bits, they can be balls, snakes, sheets, chunks, etc. You layer pieces onto your sculpture until you get the rough shape you want.

Pushing Around

This is taking your fingers and/or sculpting tools and pushing, pulling, blending, raking, and otherwise moving the clay around to refine the shapes of your sculpture.

Subtracting

Taking away clay, carving it, removing sometimes tiny slivers to refine shapes or add texture.

Isn’t there more to it?

Of course there is. There are hundreds of things to learn about sculpting specific subjects from people to animals to fabric. However no matter what you sculpt you are going to be using these basic ideas of adding, subtracting, and pushing around clay and there is no way for me to teach you to do this in an article, it requires getting your hands in the clay, playing with it, practicing creating shapes and textures to figure out what works for you.

You have to practice constantly to improve your ability to shape clay, the same way a musician practices playing scales. Its not because a scale is a piece of music anyone wants to listen to but because it’s a basic skill that improves their ability to play.

Don’t imagine I think learning things like proper anatomy, studying your subjects, etc. aren’t important. They are vital skills themselves but no amount of knowledge of anatomy is going to help if you don’t have the skill to translate that anatomy into the clay.

What Do I Do When I’ve Finished My Sculpture?

Curing

Polymer clay never dries out, in order to harden your sculpture it needs to be cured. Polymer clay cures at a fairly low temperature of around 275°F (135°C) generally in a conventional or toaster oven. I recommend the ramp method of curing sculpture which can be found on my Techniques for Curing Polymer Clay lens.

Painting

After your sculpture has cured you can choose to either leave it the color of the clay or paint it. There are many techniques you can use for painting polymer clay sculpture from light washes of color, to brushing thicker paint on, sponge painting, airbrushing, liquid polymer clays, applying soft pastels, or mica powders. My lens on Painting Polymer Clay Sculptures goes over the most common techniques.

Avoid lacquer based enamel paints, they will not dry properly on polymer clay and remain sticky. Acrylics work best, oil paints especially heat set oils are also effective.

Leave a Reply

Your email address will not be published. Required fields are marked *