Aesthetic
SLA printing produces parts and prototypes that rival injection moulding for visual quality.
Certified and compliant
ISO 9001:2015 | AS9100D
Overview
SLA 3D printing is a high-precision additive manufacturing process that uses liquid resin and UV light to produce parts with exceptional surface quality, fine detail and smooth finishes. Combined with AMufacture’s integrated manufacturing infrastructure, it becomes a powerful tool for rapid prototyping and cost-effective, low-volume production runs.
Key properties
Accurate
Enjoy greater design freedom with fine features, sharp edges and intricate geometries.
Collaborative
AMufacture integrates into your workflow, unlocking seamless collaboration at every step.
Repeatable
Parts are stored securely in your Digital Warehouse for easy repeat production.
What is Stereolithography (SLA) 3D printing?
Stereolithography (SLA) is one of the earliest and most established 3D printing technologies. It works by transforming a photosensitive liquid resin into hardened plastic using a UV laser. The laser traces the design layer by layer, resulting in highly accurate solid parts.
As an additive manufacturing process, SLA eliminates the need for tooling associated with traditional manufacturing methods such as injection moulding, enabling faster iteration and reduced lead times.
Why manufacturers choose stereolithography services
Unlike powder-based or filament-based methods, SLA printing produces parts with smooth surfaces and fine feature resolution straight off the machine.
This makes it particularly suitable for visual prototypes, master patterns and components where surface quality is critical.
Exceptional surface finish
Stereolithography 3D printing produces parts with smooth surface finishes and excellent visual quality. It often remains the optimal choice for presentation models, cosmetic prototypes and low-volume customer-facing parts.
High detail and accuracy
SLA printing excels at producing fine details, sharp edges, thin walls and intricate geometries. In terms of pure detail resolution, it outperforms fused deposition modelling (FDM), selective laser sintering (SLS) and often Multi Jet Fusion (MJF).
Broad resin property options
With a wide range of material options, SLA printing can produce parts tailored for flexibility, transparency, heat resistance and biocompatibility, allowing manufacturers to meet a variety of cross-industry use cases.
Proven industry applications
SLA 3D printing is widely adopted in the medical and dental industries, where its precision and smoothness support the rapid, cost-effective production of anatomical models and patient-specific surgical guides.
Your end-to-end stereolithography
printing service partner
When you partner with AMufacture, additive manufacturing becomes a core component of a flexible, resilient supply chain. We act as an extension of your team, offering end-to-end support from design optimisation to post-processing.
True collaborators
AMufacture is more than a contract manufacturing partner. We are strategic collaborators, offering expert design, production and post-processing support to bolster supply chain resilience and enable fast, repeatable, scalable production.
Best-in-class technology
As a leader in the additive manufacturing industry, AMufacture supports its collaborators with unrivalled access to 3D printing technologies and materials. Our robust SLA printing service is backed by one of the UK’s most advanced Multi Jet Fusion (MJF) fleets.
Digitally transformative
Our secure digital platform enables a truly collaborative partnership. Harness industry-leading design-optimisation expertise on demand, track parts in real-time throughout production and build a Digital Warehouse of components and workflows for seamless reordering.
Post-processing capabilities
Partners from the first enquiry to the perfect finish
After your parts are printed, we can offer a wide range of in-house finishing capabilities to ensure optimal performance and visual presentation. It’s all part of our end-to-end, collaborative manufacturing workflow. We handle every stage of production, transforming additive manufacturing from a point solution into an agile, always-on capability.
SLA printed parts typically undergo several finishing steps:
- Cleaning: after printing, SLA parts require rinsing in isopropyl alcohol (IPA) to remove uncured resin from the surface and support structures.
- UV curing: SLA parts typically require post-curing under UV light to enhance their mechanical and thermal properties, as the curing process is irreversible and solidifies the resin into a durable plastic.
- Support removal: the parts undergo the manual or automated removal of support structures.
Additional finishing options include:
- Sanding and polishing for enhanced smoothness
- Priming and painting for cosmetic applications
- Clear coating for transparency or UV protection
- Assembly using adhesives or mechanical fastening
These processes enhance both surface quality and functional performance.
Cross-industry expertise
AMufacture’s stereolithography printing services are trusted by partners across sectors. By enabling rapid prototyping and seamless iteration, we help our industry collaborators accelerate innovation without the costs and lead times of traditional tooling.
SLA printing knowledge bank
How does SLA 3D printing work?
SLA 3D printing operates on the principle of vat polymerisation. A build platform dips into a tank filled with liquid photopolymer resin, then a UV laser selectively cures the resin layer by layer to create a solid object.
The SLA printing process follows a precise, repeatable sequence:
- Resin preparation: a tank is filled with liquid photopolymer resin, formulated for specific material properties such as rigidity, flexibility or heat resistance.
- Layer formation: a build platform is positioned just above the resin surface, allowing a thin layer of liquid resin to form.
- UV curing: a UV laser selectively cures the liquid resin, solidifying the cross-section of the part. This process cures photosensitive polymers with high precision.
- Layer-by-layer build: the SLA 3D printing process involves a peeling step where the build platform moves up slightly after each layer is cured. This allows fresh resin to cover the previous layer before the next curing cycle begins.
- Support structures: temporary support structures are generated to stabilise overhangs and complex geometries during printing.
- Post-processing: once complete, parts are removed and cleaned of excess and uncured resin. The parts then undergo additional UV curing to achieve the final desired mechanical properties.
SLA printing capabilities and technical specifications
SLA technology is widely recognised for its accuracy and surface finish. However, like all additive manufacturing technologies, it operates within defined manufacturing constraints:
- Layer thickness: typically ranges from 25 to 100 microns, with lower layer heights providing finer detail but increasing print time and cost
- Dimensional accuracy: around ±0.2 to 0.5% depending on geometry
- Minimum feature size: ~0.2 to 0.5 mm
- Surface quality: exceptionally smooth compared to most additive manufacturing methods
- Build volumes: vary from desktop SLA printers to industrial-scale systems
SLA 3D printing produces parts with isotropic mechanical properties due to its layer-by-layer photopolymerisation process, resulting in strong, uniform strength across all axes.
Material behaviour can also vary depending on resin formulation, particularly under UV exposure, heat and long-term mechanical stress.
SLA printed parts excel in detail and finish, but they are generally less suitable for high-load functional applications compared to thermoplastics produced via SLS or MJF.
SLA 3D printing materials and typical properties
SLA materials are thermosetting polymers. That means they cannot be remelted after curing, unlike thermoplastics used in other 3D printing methods.
They are based on liquid photopolymer resin systems engineered for specific applications:
- Standard resins: good surface quality, suitable for visual models
- Tough resins: improved impact resistance and durability
- Flexible materials: rubber-like properties for seals and grips
- High-temperature resins: elevated heat deflection temperature
- Biocompatible materials: suitable for medical and dental use (subject to certification)
Typical material properties include:
- High resolution and fine detail
- Smooth surface finishes
- Moderate strength compared to thermoplastics
- Sensitivity to prolonged UV exposure
SLA resins are ideal for aesthetics and precision, though they may require validation for long-term functional use. They are also often formulated to exhibit a wide range of mechanical properties, including high heat deflection temperature and impact resistance, making them suitable for various applications.
SLA is often used to support secondary materials like glass or ceramic to enhance specific properties, such as heat deflection or impact resistance.
SLA vs FDM printing
SLA and fused deposition modelling (FDM) differ significantly in output and application:
- Surface finish: SLA produces smooth surfaces, while FDM parts generally exhibit more pronounced layer lines
- Accuracy: SLA offers finer detail and tighter tolerances
- Materials: FDM uses thermoplastics, while SLA uses liquid resin
- Strength: FDM parts are typically more robust for functional use
SLA is preferred for appearance and precision, while FDM is often chosen for cost-effective, durable prototypes.
SLA vs MJF printing
SLA and Multi Jet Fusion (MJF) are designed for different manufacturing priorities:
- Surface quality: SLA delivers smoother surfaces and finer cosmetic detail; MJF parts have a slightly textured finish
- Production efficiency: MJF is significantly faster and more scalable for batch production
- Material properties: MJF parts are stronger and better suited to functional end-use applications
- Support structures: SLA requires supports; MJF does not
- Detail resolution: SLA offers superior fine-detail accuracy and sharper feature definition
SLA is ideal for visual prototypes and intricate, high-precision components, whereas MJF is better suited to the rapid, repeatable production of functional parts.
SLA printing design guidelines
Designing for SLA printing can significantly improve outcomes and reduce quoting friction. AMufacture provides design optimisation support as standard, helping refine geometries for SLA technology while balancing performance, cost and manufacturability.
Wall thickness:
- Minimum ~0.5 to 1.0 mm recommended depending on geometry
Feature size:
- Fine details should be ≥0.2 to 0.5 mm for reliable reproduction
Supports:
- Design with support removal in mind to minimise post-processing marks
Hollowing:
- Hollow large parts to reduce material usage, ensuring drainage holes for uncured resin
Orientation:
- Part orientation affects surface quality and support placement
Tolerance considerations:
- Allow clearance for mating parts, typically ~0.2 to 0.3 mm
SLA Printing FAQs
What is the difference between bottom-up and top-down SLA printers?
Bottom-up SLA printers cure thin layers of resin from below using a transparent tank, while top-down systems cure from above and are typically used for larger, industrial builds.
How stable are SLA printed parts over time?
SLA parts can degrade or become brittle with prolonged UV exposure unless properly post-cured and protected.
That’s one reason SLA is often preferred for projects where aesthetics and precision are more critical than raw durability.
Can SLA printing produce transparent parts?
Yes, certain SLA resins can produce highly transparent parts when polished and finished correctly.
How does SLA compare to digital light processing (DLP)?
Both are good 3D printing options for rapid prototyping. However, SLA uses a UV laser to cure resin point-by-point for high precision, while digital light processing (DLP) cures entire layers at once, typically making it faster but slightly less precise for fine details.
Explore more services
With AMufacture’s best-in-class 3D printing fleet, you unlock more ways to deliver on production goals and bolster supply chain resilience.
Multi Jet Fusion (MJF)
A powder-based process that uses fusing agents and thermal energy to produce strong, consistent parts with exceptional speed and batch-production efficiency.
Best for: end-use parts, scalable production, rapid iteration
Digital Light Processing (DLP)
A resin-based process that harnesses projected light to cure entire layers in one go, enabling rapid production of highly detailed parts.
Best for: fine detail, small parts, smooth finishes
Selective Laser Sintering (SLS)
A powder-based process that uses a laser to fuse nylon materials into strong, functional parts without support structures.
Best for: large components, lighter colours, small production runs
Fused Deposition Modelling (FDM)
A material extrusion process that uses durable thermoplastics to build parts layer by layer.
Best for: large components, durability, tooling
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