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🗿 Polymer Clay

Updated at 2022-09-25 02:30

Polymer clay is a type of oven-baked modelling clay. Sculpt it on your own time, optionally even store for a while and cure it in with heat when you feel like it.

Polymer clay is a mixture of PVC particles and oily plasticizer. When it's baked, the plasticizer burns off and the particles fuse together to a sturdy plastic.

PVC: polyvinyl chloride

Most polymer clay brands have their origins in doll-making, but all have since generalized to "modelling clay".

All polymer clay works more or less the same, but you start to like certain brands because e.g. the consistency, the finish or how the colors mix together.

Jewelry:                Fimo, Premo, Sculpey III
Dollhouse Accessories:  Fimo, Premo, Sculpey III
Scale Models and Dolls: Super Sculpey

There are liquid polymer clay. The thick liquid bakes into a semi-transparent solid. Thin layers are surprisingly see-through.

Metallic (mica dust) and glow-in-the-dark clay are things too.

Ceramic tiles are awesome. 20x20 cm floor tile is good for a working area. You can both move and bake your creations on the tiles. Baking on a tile makes heat distribute more evenly.

It's still worth using 2 tiles, one for working and one for baking. Cover the baking tile with a parchment paper so the finished clay doesn't get a shine spot where it touched the tile.

Use rubbing alcohol for clean up. Rubbing alcohol dissolves uncured clay easily.

The warmer the clay is, the softer it gets. Conditioning the clay is essential before working on it.

if you press clay ball flat, does it crack from the edges?

You can use paper if your clay gets too soft to work with. Make a sheet from the clay and place it pressed between two papers for 30 minutes. The paper will soak some oils so the clay becomes slightly harder.

Basic Shapes:

  • ball: roll a ball between your palms
  • disc: roll a ball and press between you fingers
  • cylinder: roll a ball and roll a cylinder against a flat surface, level the ends
  • sheet: make a thick disc and pinch pull edges to a square
  • snake: make a cylinder and keep rolling
  • spiral: make a thin snake, flatten it, pinch either end and twist (whipped cream)

Creating more even clay sheet:

  • stack ice pop sticks to two equally high stacks
  • place a clay ball between the stacks
  • roll over using the stacks as the support
  • optionally cut away excess before the last roll to also make it a certain shape

You can paint baked polymer clay with normal acrylic paints. It's wise to varnish your creation afterwards as paints can wear off quite easily.

You can use silicone moulds with polymer clay. If you do not want to bake the mould in the oven or otherwise want to remove the clay from the mould before baking, place them in a freezer for a couple of minutes. This will harden the clay for a while, so it's easier to pop out.

You can use cornstarch to reduce how much clay sticks on things. For example, you can spread a bit of cornstarch on your silicone moulds to make the clay come out easier.

Mixing

You can do color mixing with polymer clay. How well they mix depends on the brand and the colors.

Translucent white dilutes the color.
Opaque white creates pastel colors.

You can mix polymer clay brands. Bake with the lowest temperature as the reference.

Marbling is deliberately incomplete color mixing that preserves distinct streaks.

+ 2 snakes
+ twist into a single stick
+ wad into a ball
+ roll smooth
+ roll to a snake

Baking Polymer Clay

Don't blindly trust your oven. On the first couple of times, check your oven temperature with a separate thermometer. Ovens rarely run on the exact temperature they report, so it's a good idea to test the difference.

Don't inhale the slightly toxic fumes that result from baking polymer clay. You can use disposable aluminum foil roasting pans with a similar pan on top to reduce how much fumes are released to the air. Not strictly required but recommended as a safety measure.

Aluminium tent might reduce burning. Fold a tent from foil and place on top of your creations.

Quench your creations for extra strength:

  • fill a metal can with cold water and ice cubes
  • drop a freshly baked model in the can
  • wait, 2 min

Varnishing

Polyurethane varnish is the best and cheapest varnish. It's the same thing that is used to seal wooden floors aka. floor wax. Most of them are glossy, but they sometimes come in satin. If you can choose, use the water-based variant.

Sources

  • The Polymer Clay Cookbook by Susan Partain and Jessica Partain
  • YouTube