Polymer clay works on a completely different principle from epoxy putty. Nothing is mixed and nothing starts curing, so the material stays soft for as long as you want to work it — days, if the sculpt needs it — and hardens only when baked at a low temperature. That makes it the natural choice for large or slow sculpts, and the wrong choice for anything attached to a styrene kit, which will not survive an oven — a room-temperature epoxy is the material for that job. Because it sets only in the oven, a sculpt is built over a wire armature and baked in stages, each hardened section becoming the support for the next. Wire, armatures and the rest of the branch are indexed in sculpting tools and materials, and the soft-tipped tools that smooth a surface without dragging it in silicone shapers.
