Rapid prototyping · Updated 2026-10-14
FDM vs SLA vs SLS vs MJF: 3D Printing Process Comparison.
A side-by-side comparison of the four main plastic 3D printing processes, with a table of accuracy, finish, materials, strength and cost.
FDM, SLA, SLS and MJF all build parts layer by layer, but they differ in accuracy, surface finish, materials, strength and cost. The quick answer: use FDM for low-cost functional parts and larger prototypes, SLA/MSLA resin for small detailed parts with a smooth finish, and SLS or MJF for strong nylon parts, complex shapes and small production batches. The comparison table below gives typical values for each process. PakMEC offers all four, so you can choose the right one for each part.
FDM vs SLA vs SLS vs MJF comparison table
Values are typical ranges from manufacturer design guides. Exact results depend on the machine, material, part size and orientation.
| FDM | SLA / MSLA resin | SLS | MJF | |
|---|---|---|---|---|
| How it works | Melts and extrudes plastic filament | Cures liquid resin with a laser or masked UV light | Laser sinters nylon powder | Fusing agent and heat fuse nylon powder |
| Typical accuracy | ±0.2 to 0.5 mm | ±0.1 to 0.2 mm | ±0.3 mm | ±0.3 mm |
| Layer height | 0.1 to 0.3 mm | 0.025 to 0.1 mm | About 0.1 mm | About 0.08 mm |
| Minimum wall | 0.8 mm | 0.6 mm (supported) | 0.7 mm | 0.7 mm |
| Surface finish | Visible layer lines | Smooth, fine detail | Matte, slightly grainy | Matte, usually grey or dyed black |
| Support structures | Needed for overhangs past about 45° | Almost always needed | Not needed (powder supports the part) | Not needed |
| Strength | Weaker between layers (Z-axis) | Depends on resin; standard resins are brittle | Strong and fairly even in all directions | Strong and fairly even in all directions |
| Common materials | PLA, PETG, ABS, ASA, TPU, nylon, carbon-fibre blends | Standard, tough, flexible, castable, high-temperature resins | PA12, PA11, TPU | PA12, PA11, TPU |
| Relative cost for one part | Lowest | Low to medium | Medium to high | Medium to high |
| Best for | Brackets, jigs, enclosures, fit checks, large parts | Small detailed parts, presentation models, moulds, dental and jewellery masters | Functional nylon parts, snap fits, complex internal shapes | Batches of functional nylon parts, clips, housings |
FDM: low-cost functional prototypes
FDM (fused deposition modelling) pushes melted filament through a nozzle and builds the part one line at a time. It is the cheapest option for most single parts and the only one that prints large parts economically. Layer lines are visible, and parts are weaker when pulled apart along the layers, so orientation matters. Use it for enclosures, brackets, jigs, robot chassis and early fit checks. For material choice, see PLA vs PETG vs ABS vs TPU.
SLA and MSLA resin: fine detail and smooth surfaces
Resin printers cure liquid photopolymer one layer at a time. SLA uses a laser, and MSLA uses an LCD mask over a UV light. Both capture small text, thin features and smooth curves far better than FDM. Parts need washing and UV curing, and most need supports that leave small marks. Standard resins are brittle and soften with heat, so pick a tough, flexible or high-temperature resin for functional parts. See resin 3D printing materials for the options.
SLS: strong nylon parts without supports
SLS (selective laser sintering) uses a laser to fuse nylon powder. The surrounding powder holds the part up, so there are no supports and you can print interlocking parts, internal channels and many parts packed in one build. Parts are tough and suitable for end use. The surface is matte and slightly grainy, and can be dyed or smoothed.
MJF: nylon parts for small batches
MJF (Multi Jet Fusion) spreads a fusing agent onto each powder layer and fuses it with heat. Like SLS, it needs no supports. MJF parts usually have a slightly smoother, more uniform surface and come out grey, often dyed black. It is economical when you need tens or hundreds of the same nylon part. For a closer comparison, see SLS vs MJF for nylon PA12.
What changes the price and the turnaround
No process is always cheapest or fastest. The total depends on:
- Part volume and height: tall parts take longer on every process, and solid parts use more material.
- Supports and orientation: FDM and resin parts with many overhangs need more support material and cleanup.
- Quantity: SLS and MJF become cheaper per part when many parts share one build.
- Post-processing: resin washing and curing, support removal, sanding, dyeing or painting all add time.
- Delivery: courier time to your city is separate from production time.
Which process should you choose?
- Early fit check or large part on a budget: FDM in PLA or PETG.
- Small part with fine detail or a display finish: SLA/MSLA resin.
- Functional part with snap fits, hinges or complex internal shapes: SLS or MJF nylon.
- The same nylon part in a batch of 20 or more: MJF or SLS.
- Part that sees heat, such as inside a car in summer: ASA or nylon. Avoid PLA and standard resin.
If you are unsure, send PakMEC the CAD file and a line about what the part must do. An engineer will recommend a process and material and quote it. For design limits per process, see the wall thickness and tolerance chart. Further reading: Formlabs: FDM vs SLA vs SLS and Formlabs: MJF vs SLS.
Frequently asked questions
Which 3D printing process is cheapest?
For a single small or medium part, FDM is usually the cheapest. For many identical nylon parts, SLS or MJF can cost less per part because many parts fit in one build. Compare quotes for the same file, material and finish.
Is SLA stronger than FDM?
Not usually. Standard resin is stiff but brittle. FDM parts in PETG or nylon are tougher, though weaker between layers. Tough and engineering resins narrow the gap.
Is MJF better than SLS?
Neither is better for every part. MJF often gives a more uniform surface and lower cost in batches; SLS offers more material and colour options on some machines. Both make strong PA12 nylon parts without supports.
Does PakMEC offer SLS, MJF and metal printing?
Yes. PakMEC offers FDM, SLA/MSLA resin, SLS, MJF and metal 3D printing. Share your file and requirements and the team will recommend the most suitable process.
Need help with the next step?
Need a part 3D printed?
Send your CAD file and a line about what the part must do. PakMEC prints in FDM, resin, SLS, MJF and metal, and an engineer will recommend a process and quote it.