Formlabs Form 4 Tough 1000 Resin is a ductile, impact-resistant material matching the strength and stiffness of high-density polyethylene (HDPE), but engineered for superior wear and fatigue resistance.

It outperforms HDPE with a 180% elongation at break (EAB) and a Gardner impact strength of 128 in-lb, making it ideal for parts that must bend, compress, or deform without cracking. Functional components, such as hinges, withstand repeated stress thanks to a work of fracture of 3,200 J/m² and Ross flex fatigue exceeding 100,000 cycles (at 23 °C). The resin cures to a matte dark grey finish, suitable for smooth, low-friction applications.

Developed for Form 4 Series printers, this new formulation significantly improves upon previous Durable Resin, offering five times the fracture toughness, double the EAB, and enhanced resistance to temperature, creep, and aging.