How Do You Mold Polymer Clay By Hand?
Polymer clay is a modeling and sculpting material made from PVC resin, commonly used for making decorative pieces, jewelry, miniature figurines, and other crafts. Unlike traditional clay that requires firing, polymer clay hardens when baked at relatively low temperatures, usually around 265°F.
The history of polymer clay dates back to 1939 when the first PVC-based modeling compound was developed by the German company Bayer. However in the late 1950s, an American named F.V. Carpenter further refined PVC compounds, creating a non-toxic, flexible modeling material. Carpenter founded the Sculpey brand in 1969, which helped popularize and commercialize polymer clay use in arts and crafts.
Today there are many types of polymer clay available in a rainbow of colors. Some popular brands include Sculpey, Fimo, Premo, Cernit, and Kato Polyclay. Each brand has unique properties in terms of texture, flexibility, detail ability, and more. Polymer clays come in a variety of forms including solid blocks, marbled mixtures, translucent, pearlescent, metallic, and glow-in-the-dark.
Supplies Needed
To get started sculpting with polymer clay, you’ll need a few basic supplies:
Clay Brands and Types
Popular brands of polymer clay include Sculpey, Fimo, Kato Polyclay, and Cernit. Each brand comes in a variety of colors, transparencies, textures, and material properties like flexibility vs. firmness. Look for clays that are labeled as “polymer clay” or “oven-bake clay”. Avoid air-dry or cold porcelain clays. For beginners, Sculpey III or Premo are good choices as they are easy to condition and have minimal stickiness.
Clay Tools
Useful tools include:
- Acrylic roller for conditioning clay
- Clay blade or knife for cutting clay
- Loop tools for sculpting details
- Clay shaping tools like balls, discs, or ribs
- Toothpicks for poking holes or markings
- Silicone tipped clay shapers for smoothing
Work Surface
Cover your work area with a smooth silicone mat, ceramic tile, or glass to keep the clay from sticking as you sculpt. Avoid porous surfaces like wood or paper. Some people also use cornstarch or talcum powder to reduce stickiness.
Other Supplies
Additionally, you may want:
- Acrylic paints for adding color
- Gloss glaze or varnish for finishing
- Super glue for bonding pieces
- Aluminum foil or wire armature for support
Conditioning the Clay
Properly conditioning polymer clay is a crucial first step before sculpting. Conditioning blends the ingredients together thoroughly and warms up the clay, making it soft and malleable so it’s easier to work with.
Conditioning by hand takes some elbow grease but doesn’t require any special tools. Start by kneading the clay to warm it up. Press firmly and push the clay between your fingers. Fold the clay over itself and continue kneading until it becomes smooth and uniform in texture. This helps blend any color streaks and ensures the clay doesn’t crack when sculpted. Aim to condition for at least 5-10 minutes.
Using a clay conditioning machine or pasta machine speeds up the process. Run the clay through the machine on the thickest setting several times, folding the clay over itself between passes. Then run it through progressively thinner settings until the desired softness is reached. This evenly blends the clay in minutes compared to hand conditioning.
Properly conditioned polymer clay should be soft, pliable, and have a smooth, elastic texture with no color variations. Well conditioned clay is easier to sculpt smoothly and in fine detail without cracks. Don’t skip this step for best sculpting results.
Sculpting Basics
When sculpting with polymer clay, there are some basic techniques for shaping and manipulating the material that are good to know. Here are three of the most common sculpting basics:
Rolling, Cutting, and Slicing Clay
After conditioning your clay, you can use a rolling pin or acrylic rod to roll it out flat. This allows you to achieve an even thickness for working on projects. Use an tissue blade, craft knife, or clay cutter to cleanly cut shapes and slices out of the flattened clay. Roll out varying thicknesses of clay as needed for different effects.
Making Coils, Snakes, and Rods
Roll portions of clay between your palms or on a flat surface to create long coils or “snakes.” These can be used to make rings, bracelets, hanging earrings, and more. You can also use a clay gun or pasta machine to extrude rods and tubes of clay.
Blending and Smoothing Seams
When joining pieces of clay, blend and smooth the seams by gently working the clay with your fingers, a tool, or liquid clay softener. Make sure seams are fully blended so they don’t show in the finished piece. This helps create a cohesive look.
Shaping the Clay
When hand molding polymer clay, there are several techniques you can use to shape it into anything you desire. Here are some of the most common hand shaping methods:
Hand Molding Techniques
Rolling the clay between your palms or on a flat surface with an acrylic roller can flatten it into a sheet or stretch it into a snake shape. You can pinch off sections and roll them into balls or teardrops. Use your fingers to smooth seams and blend the clay.
For detailed sculpting, start with a basic shape then add or remove clay to refine the form. Use sculpting tools to carve lines or textures. Bake the clay intermittently to harden sections as you work.
Using Molds
Press clay firmly into silicone molds to easily reproduce shapes like flowers, leaves or geometric designs. Release the cured clay shape from the mold after baking. Flexible molds work for multiple castings. You can also improvise household objects as molds.
Cutters and Stamps
Cookie cutters, stamps and shape cutters provide an easy way to cut uniform clay pieces. Press the cutter straight down through a slab of conditioned clay to cut shapes like circles, stars or hearts. Clay stamps can imprint designs like bricks, wood grain or other textures.
Texturing the Clay
Texturing is a fun way to add interest and realism to your polymer clay sculptures. There are many techniques for creating beautiful textures.
Impressing Objects
Found objects like coins, buttons, rubber stamps, cutlery, leaves, seashells, and lace can be pressed into the clay to imprint patterns and designs. Make sure the objects are clean and dry first. Press firmly and evenly into the clay, but not so deep that the clay becomes too thin in that area.
Using Tools
There are many clay sculpting tools like rollers, molds, cutters, and silicone brushes that can create fake wood grain, scales, pebbled effects, crumpled paper, layered rock, basketweave, and more. Drag, roll, or stipple the tools through the clay. Rotate the clay periodically for even coverage.
Faux Techniques
Use acrylic paints, inks, or chalk pastels to create faux effects like marble, turquoise patina, rusted metal, and more. Rub powders like mica powder or eyeshadow into the clay for a shimmery look. Use rubber stamps with embossing powder to create tone-on-tone designs.
Baking Instructions
Properly baking your polymer clay creation is essential to finishing your piece. When baking polymer clay, there are a few key factors to keep in mind:
Oven Requirements
You’ll need an oven that can maintain a consistent temperature. Many polymer clays require baking around 130°C/275°F, so your oven needs to be capable of properly reaching and holding this temperature.
Baking Times and Temps
Follow the manufacturer’s instructions for baking times and temperatures. Thinner items may only require 15 minutes of baking, while thicker pieces may need over an hour. Generally, baking at 130°C/275°F for 30-45 minutes is a good starting point.
Prevent Burning/Cracking
To prevent burning or cracking:
- Preheat your oven fully before baking.
- Don’t overbake pieces – check frequently near the end time.
- Bake evenly by rotating periodically if needed.
- Allow pieces to cool completely before handling.
With proper baking, your polymer clay creation will cure fully and be ready for the finishing touches.
Finishing Techniques
Once your polymer clay creation is baked and cooled, you will likely want to smooth and finish the surface for a professional look. Here are some of the most common finishing techniques for polymer clay:
Sanding
Sanding is one of the best ways to smooth rough or uneven surfaces on baked polymer clay. Start with a medium grit sandpaper around 400 and gently rub over the entire surface. You can then move to finer grits, like 600 or 800, for an ultra-smooth finish. Sanding will remove any small imperfections left after baking.
Buffing
After sanding, buff your polymer clay creation with a buffing wheel or cotton cloth buffing pad. This will give the surface a nice sheen and smoothness. Use a buffing compound or rubbing compound while buffing for best results. Buff until you achieve your desired level of glossiness.
Varnishing
Applying a varnish as a top coat will give your polymer clay added protection and durability. Polymer clays are naturally durable, but varnishing provides extra insurance against scratches, scuffs and fading over time. Use a water-based polyurethane varnish and apply 2-3 thin coats with a soft brush, allowing each coat to fully dry in between. This will give a beautiful glossy finish.
Advanced Techniques
Once you have mastered the basics of sculpting with polymer clay, there are many advanced techniques you can try to take your creations to the next level:
Caning
Caning involves creating thin sheets of clay, cutting them into strips, and stacking the strips to create patterned canes. The canes can then be sliced to reveal intricate designs. Caning allows you to create sophisticated patterns and effects in your clay sculptures.
Mokume Gane
Mokume gane, which means “wood grain” in Japanese, is a technique that allows you to mimic the look of woodgrain in your polymer clay. You stack and manipulate layers of colored clay to create swirling, flowing patterns when sliced.
Inclusions
Adding inclusions like beads, seeds, or small toys to your polymer clay before baking can add interesting textures and dimensions. Make sure any items you include are heat-resistant up to the baking temperature of the clay.
Mixing Colors
By mixing together different colors and types of polymer clay, you can create completely custom colors and effects. Try blending clays to achieve marbled, swirled, and gradated colors in your finished pieces.
Troubleshooting
When working with polymer clay, you may run into some common issues. Here are some tips for troubleshooting problems:
Cracking
If your sculpted clay cracks or breaks apart, the clay may have dried out too much. Make sure to keep unused clay wrapped up tight. Knead in some translucent liquid polymer clay or clay softener to help recondition overly dry clay.
Burning
If the clay scorches or burns in the oven, reduce the baking temperature and bake for a longer time. Place a sheet of parchment paper or aluminum foil underneath the clay while baking to prevent bottom scorching.
Color Blending Issues
When blending clays, work the clays thoroughly together to evenly mix the colors. Twist or roll the clays together. If needed, add some translucent clay to soften and further blend the colors.
Sculpting Problems
If the clay is sticky or globs together, knead in some cornstarch or baby powder. For smoothing issues, use rubbing alcohol. Avoid overworking the clay and reshaping excessively, as this can alter the clay’s texture.