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Resin Printing

Unrivaled precision, flawless surface finishes, and microscopic detail for prototypes that demand presentation-grade perfection.

Small and Highly Detailed Resin Prints

How is Resin Printing (SLA) Different?

 

Benefits of Resin Printing:

  • Exceptional Detail and Resolution: SLA printing is unmatched when it comes to capturing microscopic details, sharp edges, and intricate textures. It is the go-to technology for jewelry casting, dental models, and presentation-grade prototypes.

  • Flawless Surface Finish: Unlike FDM (filament) printing, which leaves visible layer lines, SLA prints cure with a perfectly smooth, glass-like finish that often looks and feels like a professionally injection-molded part right off the build plate.

  • High Dimensional Accuracy: Because the resin is cured by a highly precise UV laser at room temperature, SLA parts don't suffer from the extreme thermal expansion and contraction (warping) that plagues FDM plastics during the printing process.

  • Isotropic Strength: SLA parts cure as one continuous, solid mass. This means the structural strength of the part is the same in every direction, completely eliminating the "Z-axis weakness" common in filament printing where layers can easily split apart.

  • Specialized Material Options: The SLA ecosystem offers highly specialized photopolymers, including crystal-clear resins for optical lenses, rubber-like flexible resins, castable wax resins, and ultra-high-temp engineering resins.

 

Drawbacks of Resin Printing:

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  • Extensive Post-Processing Required: A completed print is not a finished part. It comes out of the printer covered in toxic, sticky liquid resin that must be thoroughly washed in isopropyl alcohol (IPA) and then baked in a dedicated UV curing station before it can be safely handled.

  • Brittle Standard Materials: While tough engineering resins exist, standard SLA resins are notoriously brittle and lack the impact resistance of FDM materials like PETG or PP. They will easily shatter if dropped or subjected to heavy mechanical stress.

  • UV Degradation: Because the resin is photopolymerized by ultraviolet light, leaving an unpainted SLA part exposed to direct sunlight will cause it to continue curing until it becomes hopelessly brittle, discolors, and eventually cracks.

  • Messy and Toxic Handling: Uncured liquid resin is toxic, gives off harsh fumes, and is a strong skin irritant. Printing requires dedicated ventilation, nitrile gloves, safety glasses, and strict hazardous waste disposal protocols (you cannot pour waste down the drain).

  • Smaller Build Volumes: Desktop and benchtop SLA printers typically have much smaller build areas compared to similarly priced FDM machines, limiting the maximum size of a single printed part.


SLA printing is challenging, but the rewards are awesome - When clients need small prints with a high level of detail, we often recommend SLA printing because it gladly accepts the challenge!

Learn More About Resin Printing

How Does SLA Resin Printing Differ from FDM Printing?

The core difference lies in the technology itself. While FDM (Fused Deposition Modeling) printers push melted plastic filament through a heated nozzle to build a part, SLA (Stereolithography) uses a highly precise ultraviolet laser to cure liquid plastic. The laser traces the cross-section of your part into a vat of photopolymer resin, hardening it layer by microscopic layer.

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Because SLA uses a laser beam rather than a physical nozzle, it can achieve a level of resolution and detail that FDM simply cannot match. Standard SLA prints feature layers as thin as 25 microns—a fraction of the thickness of a human hair. This results in a flawlessly smooth, glass-like surface finish that completely eliminates the visible layer lines typical of filament printing.

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Furthermore, the way the layers bond is fundamentally different. FDM parts often suffer from "Z-axis weakness," meaning they can split along the layer lines under heavy stress. SLA parts, however, undergo chemical cross-linking during the UV curing process, creating an isotropic part. This means the completed prototype has the exact same structural strength in every direction.

Are SLA Resin Parts Strong Enough for Functional Prototyping?

The answer depends entirely on the exact type of resin used. Standard SLA resins are engineered primarily for high detail and rapid printing, making them exceptional for visual models but relatively brittle. If you drop a part printed in standard resin onto a concrete floor, it will likely chip or shatter, making it unsuitable for rugged, load-bearing mechanical tests.

 

However, the materials science behind SLA has advanced massively, introducing a wide array of "Engineering Resins." By swapping the liquid in the vat, an SLA printer can produce parts that mimic the mechanical properties of injection-molded ABS, flexible rubber, or even glass-reinforced plastics. "Tough" resins offer high impact resistance, while "High-Temp" resins can withstand environments exceeding 200°C without deflecting.

 

Therefore, if you need a functional snap-fit enclosure, a custom gasket, or a complex bracket that also requires microscopic precision, SLA can absolutely deliver. The key is communicating the exact physical demands of your prototype so that the correct specialized photopolymer is selected for the build.

Why Do SLA Parts Require Specialized Post-Processing?

Unlike FDM printing, where a plastic part can often be pulled off the build plate and used immediately, an SLA print is only halfway done when the printer stops. When the build platform rises from the vat, the completed prototype is coated in uncured, liquid resin. It is sticky, messy, and cannot be safely handled without nitrile gloves and safety glasses.

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The first step in post-processing is a thorough chemical wash. The part must be submerged and agitated in highly concentrated isopropyl alcohol (IPA) or specialized solvents to dissolve the excess liquid resin. If this step is skipped or rushed, residual resin will pool in microscopic crevices and ruin the fine details the printer worked so hard to achieve.

 

Once clean and completely dry, the part must undergo final UV curing. The prototype is placed into a heated chamber lined with high-intensity ultraviolet lights. This final bake forces the polymer chains to finish cross-linking, transforming the part from a slightly soft, "green" state into its final, hardened mechanical properties. Only after this rigorous process is the prototype completely safe to handle.

What Are the Best Applications for SLA Resin Printing?

SLA printing is the undisputed king of presentation-grade modeling. When you need a prototype to look and feel exactly like a finished, injection-molded consumer product for a trade show, a marketing photo shoot, or an investor pitch, SLA is the clear choice. Its perfectly smooth surface is ready for professional painting, polishing, and finishing right out of the curing chamber.

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It is also the go-to technology for micro-mechanics and highly intricate geometries. Industries like dentistry, jewelry manufacturing, and medical device prototyping rely heavily on SLA. Whether it's printing a microscopic gear assembly or a castable wax pattern for a custom ring, the UV laser can resolve sharp edges and tiny features that would turn into a melted blob on a standard FDM printer.

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Finally, SLA is excellent for fluidic and waterproof applications. Because filament prints consist of thousands of extruded lines, they often contain microscopic gaps that allow air or water to seep through. Because SLA resin cures as a solid, continuous mass, parts are inherently watertight, making them perfect for custom manifolds, optical clear lenses, or fluid flow testing.

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