Thermoplastic

A material that softens when heated and hardens again when cool, used by cosplayers to shape armour pieces, props, and structural details.

Thermoplastics are materials that become pliable when you apply heat and then return to a rigid state as they cool. Because this cycle can be repeated many times, you can reheat a piece you are not happy with and reshape it rather than starting over. Cosplay-friendly versions come as sheets, fabrics and pellets under several brand names, each with its own working temperature and texture. Always check the specific product's instructions for the correct heat range rather than assuming one sheet behaves like another. When working with any heat-activated material, keep safety front of mind. Use a heat gun in a well-ventilated space, point it away from yourself and others while it warms up, and use silicone finger covers or heat-resistant gloves to handle the softened material — freshly heated thermoplastic holds heat longer than it looks. Younger makers should work alongside an experienced adult whenever a heat gun is in use.