Need help choosing the strongest Formlabs MSLA resin for your application? This guide compares the highest-strength resins in the Formlabs MSLA lineup, breaking down their mechanical properties, toughness, stiffness, and ideal use cases to help you choose the best material for durable, high-performance parts.
Rigid 10K Resin
Rigid 10K Resin is the stiffest material in the Formlabs portfolio. This material is also one of the most heat resistant. It is glass-filled and designed to simulate the properties of glass-fiber-reinforced thermoplastics. The “10K” refers to its Tensile Modulus of 10,000+ MPa. It feels like ceramic or stone in the hand.
Pros: Extreme stiffness, smooth matte finish, high dimensional accuracy, heat resistant.
Cons: Very brittle. Like ceramic, it will break if dropped or bent.
Best for: Injection molds, aerodynamic test models, and heat-resistant industrial parts, and welding fixtures.
Very high (88 MPa). One of the strongest Formlabs materials.
Extreme (10 GPa). It resists deformation under load better than almost any other resin. Stiffer than most filaments and powders — even those with carbon fiber fillers.
Very low. It has almost no ductility.
Extreme. It withstands heavy loads at high temperatures (HDT ~238 °C).
Rigid 4000 Resin
Rigid 4000 Resin is a Formlabs glass-filled resin with a modulus of 4000 MPa, lower than Rigid 10K Resin. It provides high stiffness while retaining more durability and toughness than the ceramic-like Rigid 10K Resin.
Pros: Stiff and strong, polished finish, higher impact resistance than Rigid 10K Resin.
Cons: Still brittle compared to the Tough Resin Family, abrasive to print tanks over time.
Best for: Thin walls, brackets, mountings, jigs, and fixtures that need rigidity but might face minor vibrations.
Very high (69 MPa).
Low. It is brittle, but less likely to shatter than Rigid 10K Resin.
Moderate. HDT is roughly 77 °C @ 0.45 MPa.
General Purpose Resins
Formlabs General Purpose Resins (including but not limited to Color Resin, Black Resin, Grey Resin, Clear Resin, and White Resin) are versatile resins that are stiff and strong, with a modulus around 2600 MPa, depending on the color and post-curing protocol.
Pros: Available in a variety of colors, fast printing, good fine features, less brittle than PLA filaments and comparable to PETG in terms of toughness, but fully anisotropic with better Z-direction properties.
Cons: Not as strong or stiff as the filled resins, but not as tough as the Tough Resin Family or tough thermoplastics like ABS. More expensive than general purpose filaments.
Best for: Form and fit prototyping and presentation-ready models.
High (~62 MPa).
Moderate – High (2600 MPa).
Moderate. The Notched Izod of 32 J/m is higher than Rigid 4000 Resin.
Low. HDT is roughly 71 °C @ 0.45 MPa.
Tough 1000 Resin
Tough 1000 Resin is the most pliable and impact-resistant of the Formlabs Tough Resin Family. It is formulated to have comparable toughness to High-Density Polyethylene (HDPE). It offers a low modulus (stiffness) of ~1000 MPa, making it incredibly tough and wear-resistant. Like the other resins in the Tough Resin Family, Tough 1000 Resin is named after its modulus.
Pros: Extreme impact resistance (highest in the Tough Resin Family), high elongation (180%), excellent wear resistance, and a smooth, low-friction surface.
Cons: Very flexible (not suitable for rigid structural parts), lower heat resistance.
Best for: Impact-resistant jigs, squeezable prototypes, low-friction assemblies (like gears and ball joints).
Low (26.3 MPa). It yields and stretches rather than holding a heavy static load.
Low. One of the most pliable non-elastomeric materials in the Formlabs portfolio.
Extreme. With a notched Izod of 72 J/m, it rivals industrial thermoplastics and, with a high work of fracture, it is arguably the hardest resin to shatter.
Low. HDT is roughly 55 °C @ 0.45 MPa.
Tough 1500 Resin
Tough 1500 Resin is a resilient Formlabs material with strength, stiffness, and toughness comparable to polypropylene (PP), offering exceptional resistance to fractures, impacts, and shattering. It has great balance between stiffness and ductility.
Pros: Sitting in between Tough 1000 Resin and Tough 2000 Resin, it blends high toughness, strength, and stiffness, and is also safe for short-term skin contact.
Cons: Lower tensile strength than Tough 2000 Resin, while not as tough and impact resistant as Tough 1000 Resin.
Best for: Latches, flexures, dampers, clasps and buckles, self-tapping screw bosses, and hinges.
Moderate (34 MPa). It is less resistant to pulling forces than Tough 2000 Resin but more ductile.
Low to moderate (1.5 GPa). While stiffer than Tough 1000 Resin it is on the more compliant end of the spectrum and comparable to some Nylon materials.
Very high. With high Gardner impact strength and work of fracture, it absorbs energy exceptionally well without shattering.
Low to moderate. HDT is around 66 °C @ 0.45 MPa.
Tough 2000 Resin
Tough 2000 Resin is the strongest and stiffest material in the Formlabs Tough Resin Family. Formulated to rival the properties of injection molded ABS plastic, it is the go-to resin for functional prototyping when you need a part that is sturdy and holds its shape but will not shatter under stress, and is strong enough for functional jigs and fixtures.
Pros: Excellent stiffness-to-flexibility balance, resists cyclic loading (fatigue), properties similar to injection molded ABS.
Cons: Less tough than Tough 1000 Resin and Tough 1500 Resin.
Best for: Enclosures, jigs and fixtures, and functional prototypes that perform like ABS.
Moderate (40.4 MPa). It is strong enough for functional jigs, fixtures, and mechanical connectors and parts typically injection molded out of ABS.
High. It offers high fracture toughness, making it capable of withstanding drops and sudden shocks significantly better than standard resins.
Moderate. It has an HDT of 70 °C @ 0.45 MPa.
High Temp Resin
High Temp Resin has the highest HDT of any Formlabs resin. It is designed specifically for thermal stability, allowing it to withstand the heat of molding processes or hot air/fluid flow. High Temp Resin is a specialty material used almost exclusively for applications where standard plastics would melt or deform.
Pros: Extreme heat resistance (highest in class), precise detail.
Cons: Very brittle (similar to glass), absorbs moisture over time, and is difficult to post-cure.
Best for: Molds and inserts, parts exposed to hot air, gas, and fluid flow, as well as heat-resistant mounts, housings, and fixtures.
Moderate (~49 MPa). Good for holding shapes, but not for mechanical loading.
Moderate to high (2.8GPa).
Very low. Parts will shatter if dropped.
Superior. It has an HDT of 238 °C @ 0.45 MPa, making it among the most temperature-resistant 3D printing materials.
Verdict: Which MSLA Material Should You Choose For Strength?
Impact Resistance
Choose Tough 1000 Resin for prototyping impact-resistant parts.
Highest Strength
Choose CF, Rigid 10K Resin. It offers the highest tensile strength, making it strong enough to replace metal components in structural applications.
Stiffness
Choose Rigid 10K Resin. Rigid 10K Resin provides glass-like stiffness (10 GPa modulus) for precision tooling.
Heat Resistance
Choose High Temp Resin, Rigid 10K Resin. For pure heat deflection (resisting deformation at ~238 °C), the MSLA resins are superior.
If you’re having trouble choosing the right MSLA material for your application, one of our experts can help you select the material that best fits your needs.
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