Polymer clay is a synthetic modeling compound popular among crafters and artists due to its versatility and durability. This material is a type of plastisol, primarily composed of polyvinyl chloride (PVC) particles suspended in a liquid plasticizer. Unlike traditional earthen clays, polymer clay remains soft and pliable indefinitely at room temperature, offering an extended working time for intricate designs. The material only hardens permanently when exposed to specific temperatures in a conventional oven, a process known as curing. Once cured, the resulting object is a durable, water-resistant plastic that can be sanded, drilled, and painted, making it suitable for jewelry, miniatures, and home decor.
Essential Materials and Tools
Starting a polymer clay project requires a few specialized items to ensure a smooth and successful creative process. The most important material is the clay itself, which is available in various formulations from brands like Fimo, Sculpey, and Kato Polyclay, each offering different levels of firmness and flexibility. Selecting a quality brand is beneficial, as it generally provides better color saturation and post-bake strength.
A dedicated, non-porous work surface is necessary to prevent the clay from sticking and to maintain cleanliness. Options such as a ceramic tile, a sheet of glass, or a flexible cutting mat work well, as they can be easily cleaned and will not react with the plasticizers in the clay. It is important to keep the work area free of lint and dust, as the clay tends to pick up small particles easily.
Basic tools for manipulation include a sharp craft blade or tissue blade for precise cutting and slicing. An acrylic roller or a dedicated clay roller is used to flatten the clay into uniform sheets. Many artists also utilize a pasta machine, which is highly effective for quickly conditioning the clay and rolling out sheets to consistent thicknesses. Simple shaping tools, such as wooden skewers, dotting tools, and dental picks, are useful for adding fine details and texture.
Preparing the Clay for Use
The initial step before shaping begins is conditioning, a process necessary to make the clay pliable and prevent cracking during manipulation and curing. Polymer clay, especially when new or cold, can be brittle and crumbly because the PVC particles and plasticizers have settled. Conditioning involves working the clay to generate friction and warmth, which evenly redistributes the plasticizer throughout the PVC matrix.
Manual conditioning involves kneading and rolling small portions of the clay by hand until it becomes soft and stretches without breaking. For larger amounts or firmer clay types, mechanical conditioning using a pasta machine is significantly faster. The clay is repeatedly passed through the machine’s rollers, folded, and passed through again, which quickly warms the material and forces the particles to align.
This preparation phase is also the time to create custom colors by blending two or more conditioned clays together. To achieve a new, solid color, the clays must be mixed thoroughly until no streaks of the original colors remain. Ensuring the clay is fully conditioned before blending guarantees a uniform texture and color consistency in the final piece.
Fundamental Shaping Techniques
Achieving a uniform thickness is often the first technical requirement for projects like jewelry components or decorative veneers. This is accomplished by rolling the conditioned clay between two guide rails, such as wooden dowels or acrylic sticks, which act as stops for the roller. Alternatively, a pasta machine set to a specific number will produce sheets of a precise, consistent thickness, which is essential for professional results.
Creating simple, repeatable shapes like coils and beads relies on consistent pressure and motion. To make a uniform coil, a piece of clay is rolled between the palm and the work surface, applying even pressure from the center outward to create a snake-like form. For round beads, the coil can be sliced into equal-sized segments, which are then rolled individually in a circular motion within the palm of the hand until a smooth sphere is formed.
A more advanced technique is the Skinner blend, which creates a smooth, seamless color gradient from one shade to another. This process begins by rolling two or more colors into sheets, cutting them into triangles, and joining them side-by-side to form a rectangle. This sheet is then repeatedly folded and passed through a pasta machine, always feeding the folded edge first, until the colors merge into a continuous spectrum. Surface detail can be added by pressing the clay with various items, such as stamps, texture sheets, or natural materials like leaves, to create an impressed pattern before the piece is cured.
Curing and Finalizing Your Project
The curing process transforms the soft, pliable clay into a durable, permanent object through a thermal reaction. It is necessary to follow the manufacturer’s recommended temperature, which is typically around 275°F (135°C), and the specified baking time, often 15 to 30 minutes per quarter-inch of thickness. Using a separate oven thermometer is highly recommended, as household oven thermostats can be inaccurate, and under-baking will result in a weak, brittle piece.
To prevent scorching or browning, the clay should be protected from direct heat, often by covering it with an aluminum foil tent or baking it on a ceramic tile. Proper ventilation is important during curing, as overheating the clay can cause it to release irritating fumes. Once the baking time is complete, the piece must be allowed to cool completely before handling, as the clay reaches its final hardness only after it returns to room temperature.
After cooling, the project can be refined through post-baking finishing techniques. Sanding is performed using wet/dry sandpaper, starting with a medium grit, such as 400, and progressing to finer grits to remove fingerprints and surface imperfections. This wet sanding process minimizes dust and creates a smooth surface that can be buffed to a subtle sheen. For a high-gloss finish or added protection, a polymer clay-compatible glaze or sealant can be applied, ensuring the chosen product will not react negatively with the cured plastic.