Polymer modeling clay offers crafters an easier way to achieve professional results without dealing with toxic materials or expensive kilns. Working with modeling clay is relatively easy when the basic working methods of the clay are understood. For optimum results, it's best to understand condition, sculpt and properly bake your clay.
Conditioning
By conditioning clay, the clay is made more pliable and workable. When polymer clay sits dormant, it tends to become harder and sometimes brittle. This can be alleviated with conditioning.
The most common way to condition clay is through hand kneading. The kneading helps the clay to warm gradually, causing it to become softer and suppler. Clay that has been stored for awhile will be more difficult to condition at first. With continued hand conditioning, however, the clay will begin to become more pliable and will soon be easier to knead.
Another method for conditioning clay is through the use of a polymer clay dedicated pasta machine. This method takes some of the stress off the hands by using the pasta machine to roll thin sheets of clay. Placing the clay into the pasta machine, it is rolled through the machine numerous times until it is soft and workable. Depending on how cold or hard the clay is, this can take anywhere from a few rolls through the machine to more than 20. You'll know when the clay has been thoroughly conditioned by the machine when it rolls out of the machine in a smooth sheet with no jagged edges.
Sculpting
Sculpting with clay is more or less a trial-and-error endeavor. There are some tricks, however, to make more common tasks easier.
The easiest way to prepare a cylinder of clay is by rolling the clay into a ball and then placing it on a hard surface such as a work table or large ceramic tile. Begin by rolling the clay between the table and hand until it begins to take on a log shape. Continue to roll the clay, alternating positions on the log so as to avoid an hourglass effect, until the clay log is the needed size.
For spheres, the easiest way to create a uniform, perfectly round sphere is by rolling it between the hands, keeping one hand still while rolling with the other. This prevents the sphere from becoming distorted.
Baking
It is imperative to follow the directions provided by the manufacturer when baking clay. Most clays require a baking temperature of around 275°F. The exception to this is Fimo brand polymer clay, which has a new, lower baking temperature of 230°F.
Generally, clay should be baked 30 minutes for each ¼ inch thickness. It's important to carefully watch your clay as it's baking so it doesn't scorch or burn. If the clay should begin to burn and release a smoke, clear the room of all people and pets, as the fumes can be harmful.
Clay should be baked on a dedicated sheet or ceramic tile. To prevent the clay from becoming too shiny on the surface where it meets the tile or baking platform, parchment paper or a brown paper bag can be placed between the clay and the baking sheet.
Sanding and Polishing
When sanding clay, begin with a lower grit sandpaper (200) and gradually work up to a fine grit (800). Use wet/dry sandpaper and sand under running tap water or in a bowl of water to prevent polymer particle dust from releasing into the air.
Once the clay is sanded, it can be buffed to a sheen using a denim cloth or a mechanical buffing wheel. If a high gloss is needed, water-based sealers such as Varathane can be used as a varnish.
