3D printing continues to reshape modern manufacturing, and two advanced technologies SLA (Stereolithography) and SLS (Selective Laser Sintering) stand out for their precision, material performance, and industrial applications. Whether you’re choosing a professional 3D printer or understanding the difference between SLA vs SLS, this guide breaks down everything: print quality, speed, strength, materials, costs, and best use cases.
This full comparison will help you decide which one fits your requirements perfectly.
What is SLA 3D Printing?
SLA 3D printing is a precision resin-based 3D printing technology that uses a focused UV laser to cure liquid photopolymer resin layer by layer. This technology is known for delivering ultra-smooth surfaces, sharp edges, and extremely detailed features, making SLA ideal for miniatures, dental models, jewelry patterns, and high-accuracy visual prototypes.
How SLA Works
A vat of liquid UV-sensitive resin is filled.
A precise laser cures resin layer-by-layer.
The model is lifted from the resin tank.
It requires washing and UV post-curing.
Advantages of SLA
Ultra-high detail capability
Smooth, near injection-molded surface finish
Ideal for miniatures, medical models, jewelry masters
Excellent accuracy for small components
Limitations of SLA
Resin is expensive
Requires washing + curing
Brittle compared to nylon-based SLS parts
Smaller build volume
Requires safety precautions
SLA is best for models where high detail and smooth surfaces matter most.
What is SLS 3D Printing?
SLS 3D printing is an advanced powder-bed fusion technology that uses a high-power laser to selectively fuse nylon powder into solid layers. Because the surrounding unfused powder naturally supports the model, no support structures are needed making it perfect for complex geometries. SLS produces strong, durable, and production-ready parts widely used in engineering, prototyping, and industrial manufacturing.
How SLS Works
A bed of polymer powder (typically Nylon/PA12) is preheated.
A laser selectively sinters the powder layer-by-layer.
Unfused powder acts as natural support.
The part is removed, cooled, and cleaned.
Advantages of SLS
Industrial-grade strength
Durable, impact-resistant nylon parts
No supports needed (powder acts as support)
Large batch printing (great for production)
Functional prototypes + end-use parts
Limitations of SLS
More expensive machines
Powder handling requires safety + ventilation
Surface is slightly grainy
Post-processing: depowdering required
SLS is excellent for functional engineering parts and full-scale production.
SLA vs SLS 3D Printing: Detailed Comparison
If you’re comparing SLA vs SLS, here’s the complete breakdown: quality, strength, speed, cost, material choices, and ideal applications.
Print Quality: SLA vs SLS
SLA Print Quality
Ultra-smooth and glossy surfaces
Superior accuracy for small details
Excellent for tiny features (25–50 microns)
Best for dental models, miniatures, and molds
SLS Print Quality
Slightly rough (powdery) matte finish
Excellent dimensional accuracy
Great for functional components
Complex internal structures possible
If surface smoothness and tiny details matter → SLA wins.
If complex geometries and mechanical performance matter → SLS wins.
Print Strength: SLS vs SLA
SLA Strength
Brittle unless using tough/engineering resins
Not ideal for impact loads
Great for visual prototypes, not stress-bearing parts
SLS Strength
Extremely strong, durable nylon
High impact resistance
Heat-resistant and load-bearing
Perfect for functional mechanical use
In a sla vs sls strength comparison, SLS is far stronger and more durable.
Print Speed: SLA vs SLS
SLA Speed
Speed depends on layer height and surface area
Small models print fast
Large solid parts take longer
SLS Speed
Very fast for large batches
Can print many parts at once
Consistent speed regardless of part complexity
For mass production or multiple parts → SLS is much faster.
For small single parts → SLA is usually quicker.
Material Options: SLA vs SLS
SLA Materials
Standard resin
Tough resin
Dental resin
Castable resin
Flexible resin
Great for clarity, aesthetics, and precision.
SLS Materials
Nylon PA11 / Nylon PA12
Glass-filled nylon
TPU (flexible powder)
High-performance engineering powders
Perfect for strength, mechanical use, and industrial applications.
SLA vs SLS for Miniatures
SLA for Miniatures
Ultra-sharp details
Smooth surfaces straight off the printer
Ideal for tabletop models, tiny figures, jewelry
SLS for Miniatures
Stronger but rougher
Details not as crisp
Better for miniature parts requiring durability
For miniatures → SLA is superior.
SLA vs SLS for Business and Industrial Use
Choose SLA if you need:
High-detail visual prototypes
Dental/medical accuracy
Jewelry and molds
Smooth surfaces and tiny geometries
Choose SLS if you need:
Functional engineering parts
Durable prototypes
End-use production components
Batch manufacturing
Full Technology Overview
SLA
How it works: Laser cures liquid resin into solid layers.
Strengths: Extremely high detail, ultra-smooth surfaces.
Cost & Size: Lower machine cost; resin is expensive.
Limitations: Brittle parts, extensive post-processing.
SLS
How it works: Laser sinters nylon powder layer by layer.
Strengths: Industrial-grade strength, no supports, batch printing.
Cost & Size: Higher machine cost; great for large batches.
Limitations: Grainy finish, powder cleanup required.
SLA vs SLS: Side-by-Side Comparison
| Feature | SLA | SLS |
|---|---|---|
| Quality | Excellent | Very Good |
| Detail Level | Extremely High | Moderate–High |
| Strength | Brittle | Very Strong |
| Speed | Fast for single parts | Fast for batch printing |
| Material Cost | Medium–High | Medium |
| Post-Processing | Wash + Cure | Depowdering |
| Surface Finish | Smooth/Glossy | Matte/Grainy |
| Best For | Miniatures & medical | Functional engineering parts |
FAQs
Which is better in SLA vs SLS 3D printing?
It depends on your goal. SLA wins in surface quality, detail, and aesthetics. SLS wins in durability, strength, and functional real-world applications.
Is SLS stronger than SLA?
Yes. SLS nylon parts are significantly stronger, more impact-resistant, and suitable for mechanical use, while SLA resin is more brittle.
Is SLA cheaper than SLS?
SLA printers are cheaper, but resin costs add up.SLS machines are expensive, but nylon powder is cost-efficient for batch production.
What’s the difference in SLA vs SLS print quality?
SLA produces ultra-smooth, highly detailed surfaces. SLS offers strong, functional parts with a matte, powdery finish.
For 3D printing projects, quotes and more information visit KAD 3D