How to Choose the Right 3D Printing Service in the UK: FDM, SLA or SLS?

By Joshua Richardson
May 1, 2025
8:50 am

Choosing the right UK 3D printing service can be challenging, especially with the varying technologies available such as filament (FDM), resin (SLA), and powder (SLS) printing. Understanding the differences in terms of print quality, dimensional accuracy, material properties, surface finish, workflow, and cost per part is crucial for achieving the best results for your application. In addition to selecting a local or regional supplier, many companies now also consider online 3D printing services in the UK. These platforms offer instant quoting, broader material selections, and flexible lead times, making them a practical option for certain project types.

Understanding the Main 3D Printing Technologies

FDM Printing (Filament 3D Printing)

Fused Deposition Modelling (FDM), also known as filament 3D printing, builds parts by extruding thermoplastic filaments through a heated nozzle, layer by layer. FDM printing is widely used for rapid prototyping, proof-of-concept models, and cost-effective production of larger parts. It offers affordable material options and fast turnaround times for simple designs. However, FDM parts often exhibit visible layer lines and lower dimensional accuracy compared to SLA and SLS technologies. While good for early-stage prototypes, intricate or highly functional components may require alternative methods.

Materials available for FDM printing range from standard PLA and ABS, to more advanced materials such as PEEK and composites reinforced with carbon fibre or glass. This versatility makes FDM an accessible entry point for many businesses, but post-processing is often necessary to improve surface quality and appearance.

See UK government overview of additive manufacturing and 3D printing

SLA 3D Printing (Resin 3D Printing)

Stereolithography (SLA), or resin 3D printing, uses a laser to cure liquid resin into solid parts with exceptional precision and surface quality. SLA is favoured for projects requiring tight tolerances, smooth finishes, and intricate detail, making it ideal for industries such as dental, jewellery, and precision engineering.

SLA parts achieve superior dimensional accuracy, thanks to the highly controlled curing process. Materials range from general-purpose resins to specialist options offering heat resistance, flexibility, or biocompatibility. However, SLA printing involves additional post-processing, including washing and UV curing, which must be factored into project timelines and costs. Despite these additional steps, the quality and aesthetic finish of SLA parts often outweigh the complexity for many professional applications.

SLS 3D Printing (Powder 3D Printing)

Selective Laser Sintering (SLS) is a technique wherein a high-energy laser selectively fuses thermoplastic polymer powder particles by scanning cross-sections derived from a 3D CAD model. The process occurs layer by layer within a controlled environment, enabling the creation of complex geometries, including internal features and moving assemblies, without the need for support structures.

SLS parts exhibit excellent mechanical properties, with strength and durability comparable to injection moulded plastics. Nylon 12 and Nylon 11 are commonly used materials, providing chemical resistance, impact strength, and stability under varying environmental conditions. While SLS parts naturally have a slightly grainy surface texture, post-processing methods such as media blasting or vapor smoothing can improve the finish significantly. SLS is particularly well-suited to functional prototypes, production tooling, and low-volume manufacturing, especially when multiple parts can be efficiently nested within a single build.

How to Select the Right 3D Printing Technology

Choosing the correct 3D printing method requires a careful assessment of your project requirements. If you need a simple, cost-effective prototype for visual evaluation or ergonomic testing, FDM printing is often the best choice. It provides good mechanical strength at a lower price point, but parts may require sanding and smoothing to achieve a presentable finish.

Where high-detail, accurate visual prototypes or parts demanding tight tolerances are required, SLA printing becomes the preferred option. SLA’s fine resolution and smooth surface finish make it ideal for cosmetic prototypes, mould patterns, and detailed medical or dental components.

For demanding functional parts that must withstand mechanical stress or environmental exposure, SLS printing offers the highest performance. Its ability to create durable, isotropic parts without the need for support structures allows for greater design freedom and efficient batch production.

The scale of production also plays a role. FDM and SLA are suitable for single prototypes or small batches, while SLS shines when producing multiple parts simultaneously, optimising cost per part.

For a full comparison of technologies, see our FDM vs SLA 3D printer guide for more detail on how each process performs.

Material Options and Post-Processing Requirements

Material choice is another essential factor. FDM uses a variety of thermoplastics such as PLA, ABS, PETG, and reinforced composites, making it versatile but with the limitation of anisotropic strength. SLA relies on photopolymer resins, available in diverse formulations for specific applications like dental guides, flexible components, and heat-resistant fixtures. SLS primarily uses nylon powders, though flexible options such as TPU are increasingly popular for wearable or shock-absorbing components.

Post-processing requirements vary considerably. FDM parts usually need support removal and surface finishing through sanding or vapour smoothing. SLA parts require washing to remove uncured resin and a UV curing cycle to reach optimal mechanical properties, often followed by minor sanding. SLS parts need powder removal and media blasting to ensure clean, professional results, with optional surface smoothing treatments improving appearance and waterproofing.

Industrial Applications Across Sectors

Each technology excels in different industries. FDM printing remains popular for educational models, jigs and fixtures, and consumer goods prototypes. SLA printing is often used for dental appliances, hearing aids, intricate product prototypes, and low-volume manufacturing of highly detailed parts. SLS is the preferred option for aerospace components, medical devices, automotive prototypes, and end-use parts requiring durability and precision.

The ability to match material properties, part functionality, and design complexity to the correct 3D printing method ensures better outcomes, faster iteration cycles, and reduced costs over the product development lifecycle.

For expert guidance on your specific requirements

For a full overview of available UK 3D printing service options, explore the range of processes we support for different industries and part requirements.

Quick Technology Comparison

FDM (Filament)

Dimensional Accuracy: Moderate
Surface Finish: Visible layer lines
Cost per Part: Low
Speed: Fast
Ideal Applications: Concept models, large parts

SLA (Resin)

Dimensional Accuracy: Very High
Surface Finish: Smooth, detailed
Cost per Part: Medium to High
Speed: Very Fast
Ideal Applications: Functional prototypes, high-detail models

SLS (Powder)

Dimensional Accuracy: High
Surface Finish: Slightly grainy (post-processable)
Cost per Part: Medium
Speed: Fast (batch production)
Ideal Applications: Functional parts, low-volume production

FAQs

What’s the difference between SLA and FDM printing?

SLA uses a laser to cure resin into highly detailed, smooth parts with fine tolerances, making it ideal for cosmetic prototypes and precision engineering. FDM prints by extruding thermoplastic filament, resulting in stronger but less detailed parts with visible layer lines.

Is resin printing better for functional parts?

Resin printing offers exceptional detail and material options, including tough and flexible resins for functional prototypes. However, for ultimate mechanical strength and durability, powder 3D printing (SLS) or engineering-grade filaments in FDM may be better suited.

What’s the turnaround time for 3D prints in the UK?

At SGD 3D, standard projects are typically delivered within 2 to 6 working days, depending on part complexity, volume, and technology selected.

Which 3D printing technology offers the best surface finish?

SLA printing offers the highest-quality surface finishes, ideal for models where aesthetics and fine detail are crucial. SLS parts have a uniform, matte finish that can be polished, while FDM prints usually require additional post-processing to achieve a smooth surface.

What materials are available for UK 3D printing services?

We offer a wide range of materials including PLA, ABS, carbon fibre composites (FDM), general-purpose and engineering resins (SLA), and industrial-grade nylon powders (SLS) to meet the demands of diverse applications.

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