This is a list of plastics that have a soft phase and a hard phase. During their soft phase, they can be molded and sculpted like clay.†

The ability to be sculpted makes these great for hobbyists, rapid prototyping, crafting, clay sculpting, and other art.

Unlike clay, most can be drilled and sanded after curing.

[[Thermoplastic|Thermosoftening plastic]]

Plastics that arrive hard, but heat softens them. They can go hard→soft→hard many times.

[[Thermosetting polymer]]s

Plastics arrive soft, and irreversibly cure.


How strong are these for making structural pieces? Answer: a 4mm (1/6") diameter rod will support 25 lbs. That is: 0.225 megapascals. (compare to the ultimate yield strength of other plastics, and that seems kind of low... even PCL has a tensile strength of ~16MPa)

† In addition, all plastics on this page can be formed at room temperature, or nearly so. If you're willing to use an oven or a heat gun, the available plastics expands greatly, however, those plastics often can't be molded using your bare hands.