Using Tough Resin

Tough Resin simulates the tactile feel and many of the key mechanical properties of Acrylonitrile Butadiene Styrene (ABS) plastic. ABS is a very common thermoplastic that provides a good balance of strength and flexibility. Tough Resin creates strong engineering prototypes and has been developed to withstand high stress and strain. Consider using this material for works-like prototypes and assemblies, including designs with snap fit joints and living hinges. For further finishing, Tough resin can also be machined once printed. Tough Resin can be printed at 50 and 100 micron layer heights on both the Form 1+ and Form 2.

Toughness refers to a material’s ability to absorb energy before fracturing. When a tough material yields, it will undergo some deformation rather than just shattering. In other words, tough materials have a little more “give” than brittle ones.
Stress-strain curve for Formlabs Tough Resin

Toughness is also defined as the area under a stress-strain curve. Tough materials generally have a good balance of strength (the amount of stress a material can withstand) and ductility (the elongation or percentage strain). Because of this, the area under a tough material's stress-strain curve is much larger than that of a very strong material with low elongation. This has a direct correlation to the amount of energy each material can absorb before failure. Formlabs Tough Resin has lower stiffness than the Standard Resins while withstanding more elongation.

Recommended for

  • High-stress components
  • Snap-fit functions and living hinges
  • Machining
  • Cyclic loading
  • Works-like/feels like ABS prototyping
  • Geometrically accurate prototyping under load

Not recommended for

  • Very fine features or thin walls
  • Rigid or stiff prints
  • High-temperature applications
  • Constant loading

Comparison with Other Materials

  ABS Plastic1 Formlabs
Tough TOTL032
Formlabs Standard Resins (Postcured)3
Tensile modulus 2.5 GPa 2.7 GPa 2.8 GPa
Elongation 18% 24% 6.2%
Notched IZOD Impact Strength 234.9 J/m 38 J/m 25 J/m

Printing with Tough

Tough Resin should always be printed with supports, and printing directly on the Build Platform should be avoided whenever possible, due to the high likelihood that the print will be difficult to remove from the Build Platform.

For the easiest removal, remove the part immediately after printing, as the resin will still be warm and easier to get off. Should the part prove difficult to remove from the Build Platform, the platform can be heated up using a heatgun or blowdryer. After heating, the part can be more easily removed.

For very bulky parts, increase the support touch point size.


Wash your tough parts as recommended for parts printed with Standard Resins:

  • Cover the rinse tub, shake for 2 minutes and let your part soak for 10 minutes.
  • Move your part to the second rinse basket, shake and repeat for a total soak time of 20 minutes maximum.
  • Remove part(s) from rinse bucket and allow to air dry.

The Tough Resin coloration comes from a pigment, not a dye, so tough parts will not color the IPA.


Especially with tough resin, leaving parts in IPA too long may cause the parts to become flexible and weak.


Post-cure Your Part

Tough parts require a minimum of 30 minutes of post-curing under a 30 W, fluorescent lamp emitting in the UVA range (such as a nail spa) at 45°C. You may use a lower wattage curing chamber (eg a sterilizer), but your post-cure time will increase. Time to reach full post-cure may also be longer for larger parts. Refer to our detailed research on Post-Curing Prints for suggested lighting and temperature for post-curing.


Your Tough part will not reach its full mechanical properties without a thorough post-cure.

Contact Support

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