Formlabs PU Rigid 650 Resin is a polyurethane-based photopolymer material designed for Stereolithography (SLA) 3D printing, particularly optimized for Formlabs’ range of 3D printers. This resin is engineered with a unique blend of polyurethane resins, photoinitiators, and stiffness-enhancing additives.

Physical Properties

  • Density: Typically falls within the range of 1.15–1.25 g/cm³
  • Tensile Strength: Generally lies between 60-75 MPa, depending on the post-curing process
  • Heat Deflection Temperature: Often exceeds 100°C after proper post-curing, making it suitable for applications requiring thermal resistance

Aesthetic Quality

Formlabs PU Rigid 650 Resin produces prints with a smooth, high-quality surface finish. The material is often available in neutral or light colors and is excellent at capturing intricate details, making it suitable for both functional and aesthetic applications.

Durability and Usage

Engineered for high stiffness and thermal stability, this resin is particularly well-suited for structural components, engineering prototypes, and other parts requiring high rigidity and heat resistance. Its polyurethane-based composition provides a unique blend of mechanical properties, making it highly versatile for demanding applications.


The standard post-processing steps include washing the print in a solvent, typically isopropyl alcohol, to remove uncured resin, followed by UV curing to maximize mechanical and thermal properties. The material can also be sanded, machined, and painted, though specialized adhesives and coatings might be required for optimal results.

Environmental Impact

Like most SLA resins, Formlabs PU Rigid 650 Resin is not biodegradable and should be handled and disposed of responsibly to minimize its environmental impact. The material is derived from non-renewable resources, making it less eco-friendly compared to bio-based materials like PLA.

In summary, Formlabs PU Rigid 650 Resin offers a specialized, high-performance material tailored for applications requiring high rigidity and thermal stability. While it may not be the most environmentally friendly option, its unique set of mechanical properties make it invaluable for specialized and high-demand applications. Responsible handling and disposal are crucial due to its environmental considerations.

Formlabs PU Rigid 650 – Technical Data Sheet