SLA 3D printing (stereolithography) produces the smoothest surfaces and finest detail of any plastic 3D printing process. It is our first choice for appearance models, clear parts, mold masters, and detailed prototypes, and it can build parts from very small to very large. Our shop is in Coopersville, Michigan, just west of Grand Rapids, and we ship parts nationwide.
How SLA 3D Printing Works
Chuck Hull coined the term stereolithography and patented the process in 1986, then co-founded 3D Systems to commercialize it. It was the first 3D printing technology, and it is still one of the most accurate.
- A build platform sits in a vat of liquid photopolymer resin.
- A UV laser traces each layer of the part, curing the resin wherever the part needs to be solid.
- The platform moves one layer and the process repeats until the part is complete.
- Parts are washed to remove uncured resin, support structures are removed, and the parts are post-cured under UV light to reach full strength.
When to Choose SLA 3D Printing
SLA is the right choice when surface finish, detail, or clarity matter most. It works well for:
- Appearance models, trade show pieces, and photo-shoot prototypes
- Clear parts: lenses, windows, and light pipes
- Master patterns for RTV urethane casting and vacuum forming
- Patterns for metal investment casting
- Large, one-piece prototypes
- Snap fits, living hinges, and fit-check assemblies
- Medical and anatomical models
- Rubber-like and silicone parts in soft resins
- Parts that will be metal plated: the smooth SLA surface is the easiest base for copper and nickel plating, used for EMF testing, functional antenna components, and added strength
SLA or MJF? If the part has to look great, be clear, or carry fine cosmetic detail, choose SLA. If it has to survive real use, heat, and repeated loading, or you need many parts, MJF is usually the better fit. Not sure? Send us the part and we will recommend a process.
SLA 3D Printing Capabilities
| Maximum part size | Up to 55″ × 27″ × 19″ in one piece; larger parts can be printed in sections and bonded |
| Layer thickness | 0.002″ to 0.006″, depending on material and part |
| Accuracy | ±0.025″ for the first 5″, ±0.0025″ per inch thereafter (see our part accuracy page) |
| Surface finish | Smooth, with layer lines that sand and polish out easily |
| Materials | 15 resins, from ABS-like and polypropylene-like to clear, high-temperature, ESD, flame retardant, and silicone |
Accuracy depends on part size, geometry, and material. Send us your CAD file and we will give you a realistic estimate for your part.
SLA 3D Printing Materials
Each material has its own page with full mechanical properties, data sheets, and part photos.
Rigid and ABS-like
| Material | Best for |
|---|---|
| RP 105W | Opaque white parts with good accuracy and durability |
| Tough 2000 | Stiff, strong prototypes that behave like injection-molded ABS |
| White | High-accuracy, smooth white parts for presentation models |
Polypropylene-like and impact resistant
| Material | Best for |
|---|---|
| Accura 25 | Snap fits, styling parts, and urethane casting masters with a polypropylene feel |
| Accura Xtreme White 200 | Very high impact resistance; tough, flexible functional parts |
| Tough 1500 | Stiff yet pliable parts that bend and spring back, like polypropylene |
| Tough 1000 | Ductile, impact-resistant parts with an HDPE-like feel |
Clear
| Material | Best for |
|---|---|
| Accura ClearVue | Optically clear lenses, light pipes, and flow visualization; polycarbonate-like |
| Clear | Transparent prototypes and see-through housings |
High temperature and specialty
| Material | Best for |
|---|---|
| High Temp | Heat-resistant parts, molds, and fixtures, with heat deflection up to 460°F |
| Flame Retardant | UL 94 V-0 rated parts for enclosures and interiors |
| ESD | Static-dissipative fixtures and parts for electronics handling |
Flexible and elastic
| Material | Best for |
|---|---|
| Flexible 80A | Firm rubber-like parts: grips, seals, and overmold prototypes |
| Elastic 50A | Soft, stretchy parts that bounce back |
| Silicone 40A | 100% silicone parts that are soft, pliable, and durable |
Compare SLA with our other processes on the machine and material comparison guide.
Finishing Options for SLA Parts
SLA parts can be shipped with supports removed or finished all the way to paint-ready or optically clear. Our standard finish levels:
We can also paint parts to a requested color, prepare parts for copper and nickel plating, install threaded inserts, and handle other finishing and post-processing.
Designing Parts for SLA
Our engineering team at DeWys Engineering designs parts for SLA regularly. If your part isn’t ready to print yet, our design for additive manufacturing services can help, from design review to full CAD design.
If you would rather design the part yourself, we strongly recommend starting with our SLA Part Design Guide. Our engineers built it from years of SLA projects as a place to keep the lessons we have learned, and we publish it so anyone designing for SLA can benefit. It covers wall thickness, supports, hollowing, and how to get the best surface finish.
SLA handles a lot that machining and molding cannot:
- Sharp internal corners
- No draft required
- Class A surfaces that sand and paint well
- Printed threads above ½″; brass inserts can be glued in for smaller threads
- Serial numbers and text printed into each part
- Honeycomb interiors to reduce weight
- Assemblies, living hinges, snap fits, and pin hinges
- Functional light pipes in clear resin
SLA Part Examples
SLA 3D Printing FAQ
How smooth and accurate are SLA parts?
SLA produces the smoothest surfaces and finest detail of any plastic 3D printing process. Plan on ±0.025″ for the first 5″ and ±0.0025″ per inch thereafter; see our part accuracy page for details.
How big can SLA parts be?
Up to 55″ × 27″ × 19″ in one piece. Larger parts can be printed in sections and bonded.
Can SLA make clear parts?
Yes. Accura ClearVue and Clear resins make transparent parts such as lenses, windows, and light pipes. Clear parts can be finished from a simple bead blast up to an optical coat.
Are SLA parts strong enough for functional use?
Many are. Tough resins such as Tough 2000, Tough 1500, and Accura Xtreme White 200 handle snap fits, fit checks, and functional testing. For parts that must survive heat and repeated loading, or for larger quantities, MJF is usually the better fit.
Can SLA parts handle heat?
Standard SLA resins are not meant for high temperatures, but High Temp resin has a heat deflection temperature of up to 460°F and is used for heat-resistant parts, molds, and fixtures.
Can SLA parts be painted or plated?
Yes. The smooth SLA surface is an excellent base for paint, Cerakote, and copper and nickel plating. We can prep parts for paint or paint them to a requested color.
ISO 9001:2015 Certified Quality
Our quality management system is certified to ISO 9001:2015 and covers engineering, additive manufacturing, post-processing, and inspection, so customer requirements are handled consistently from quote to delivery. Learn more about our ISO 9001:2015 certification.