Polymer Clay — A Studio Medium for Costume and Artisan Jewellery
Polymer Clay — A Studio Medium for Costume and Artisan Jewellery
PVC-and-plasticiser modelling compound that bakes hard at low temperature, used outside the fine-jewellery trade
Polymer clay is a thermosetting modelling compound composed of polyvinyl chloride and plasticisers, cured by baking at low temperatures, typically 110 to 130 degrees Celsius. It is used in studio jewellery practice to create beads, pendants, focal elements, and decorative inlays, often in combination with metal findings, leather cord, and natural-stone components. Polymer clay is a non-gemstone material and sits within the costume, artisan, and craft-jewellery markets rather than within the fine-jewellery trade.
Composition and brands
The base of polymer clay is polyvinyl chloride suspended in a plasticiser carrier, with pigments, opacifiers, and rheology modifiers added to produce the working properties of the finished compound. Major commercial brands include Fimo, produced by Staedtler in Germany; Sculpey, produced by Polyform Products in the United States; Cernit, produced by Darwi in Belgium; and Kato Polyclay, formulated by polymer-clay artist Donna Kato. Each brand has somewhat different working properties — softness when conditioning, fineness of detail, strength when cured — and most studio practitioners develop preferences based on the work they do most often.
Polymer clay is supplied in a wide range of premixed colours, including translucents, metallics, and pearlescents, and can be intermixed to produce custom colours and gradients. The cured material is rigid but slightly flexible, can be drilled, sanded, carved, and painted, and can be combined with other materials in mixed-media work.
Techniques
Studio polymer-clay practice has developed an extensive repertoire of techniques, many of them adapted from glasswork or from other modelling traditions. Caning, in which coloured clay is layered into a cylindrical pattern then reduced and sliced to produce repeating motifs, is borrowed from millefiori glass technique. Mokumé gane, named after the Japanese metalworking technique, layers coloured clays then disturbs the layers to produce wood-grain or marbled patterns. Mica-shift techniques use the alignment of mica particles in pearlescent clays to produce hidden imagery visible only when the surface catches light at certain angles. Sculptural work, faux-stone and faux-organic effects, and surface-treatment methods using inks, leaf, and pastel pigments are all part of the contemporary studio repertoire.
Curing and finishing
Cured polymer clay is hard, water-resistant, and dimensionally stable, but it is not the equivalent of a fired ceramic or a metal cast. The material softens at temperatures above the cure point, can be marked by fingernail pressure, and is not suitable for applications where mechanical strength or thermal resistance are required. Finished pieces are typically sanded, buffed, and either left with a natural lustre or sealed with a dedicated polymer-clay finish; conventional varnishes and acrylic finishes are sometimes used but require careful selection because some interact poorly with the plasticisers in the clay.
In the trade
Polymer-clay jewellery is sold primarily through craft fairs, online studio retailers, and specialist galleries, with pricing reflecting the artist's reputation and the labour content of the individual piece rather than material value. Some polymer-clay artists have built recognised practices and exhibit in fine-craft contexts; others sell at a more modest price point in broader artisan markets. Polymer clay is not used in fine jewellery, where the materials standard is metal and gemstone; the language of jewellery in polymer-clay contexts refers to wearable objects rather than to fine adornment in the trade sense.
Care
Polymer-clay pieces should be stored away from direct sunlight and away from prolonged heat, both of which can cause discolouration or surface degradation. Cleaning is by soft cloth and mild soap; solvents should be avoided, since some interact with the plasticisers in the clay. With reasonable care, polymer-clay jewellery is stable for many years; with neglect, surface damage can accumulate quickly.