FDM vs SLA: which 3D printing process to choose in 2026?
FDM filament or SLA resin? Compare precision, cost, materials and finish to choose the right 3D printing process for your project.
3D printing covers two fundamentally different technologies: FDM (molten plastic filament deposition) and SLA (liquid resin polymerization by UV laser). Choosing the wrong process can waste time, money and compromise final part quality. This guide compares both technologies on the criteria that really matter.
At NC Factory in Antibes, we use both processes daily. Here is how we guide clients toward FDM or SLA based on their project.
How do FDM and SLA work?
FDM: a plastic filament (PLA, ABS, PETG, Nylon, ASA…) is melted and deposited layer by layer by a heated nozzle. Most widespread, robust and economical technology. Typical layer: 0.1 to 0.3 mm.
SLA: a UV laser solidifies liquid resin layer by layer in a vat. Significantly higher precision (layer 0.025 to 0.1 mm) and near-injection surface finish. Mandatory post-processing: isopropyl alcohol rinse and UV curing.
FDM vs SLA comparison
- Dimensional precision: FDM ±0.2 mm — SLA ±0.05 mm
- Surface finish: FDM visible (layer lines) — SLA smooth, near-injection
- Available materials: FDM very broad — SLA specialized resins
- Mechanical strength: FDM excellent with Nylon/ASA — SLA moderate, resin-dependent
- UV / outdoor resistance: FDM excellent (ASA) — SLA limited without post-treatment
- Unit part cost: FDM economical — SLA 2 to 5× more expensive
- Max volume: FDM up to 300×300×400 mm — SLA up to 200×120×200 mm
- Production lead time: FDM 24-48h — SLA 24-72h (post-processing included)
When to choose FDM?
- Functional part under mechanical stress (Nylon, ASA, PETG)
- Outdoor, UV or seawater exposure (ASA, PETG)
- Large part or significant volume
- Small batch (5 to 50 parts) with cost constraint
- Replacement part, tooling, robust prototype
- Flexible material required (TPU 95A)
When to choose SLA?
- Critical dimensional precision (notches, fine threads, micro-geometries)
- Premium aesthetic finish (presentation prototype, client model)
- Small detailed part (technical jewelry, micro-components, dental models)
- Shape validation prototype before injection molding
- Indoor part without UV constraint (electronic enclosure, architectural model)
In summary: FDM for function (strength, outdoor, batch), SLA for form (precision, aesthetics, details). Many projects combine both: SLA prototype for aesthetic validation, final FDM part in ASA or Nylon.
FAQ
Generally no. FDM in Nylon or ASA offers superior mechanical strength and UV resistance. SLA excels in precision and finish, not structural robustness.
Yes for both. FDM needs light sanding before painting. SLA, with its smooth surface, takes paint directly. We offer paint finishing on request.
FDM in ASA, without hesitation. ASA resists Mediterranean UV, seawater and temperature variations. SLA is not suited for outdoor use without specific UV treatment.
An SLA part typically costs 2 to 5 times more than an FDM equivalent, due to resin cost and post-processing. For a 5 cm clip, expect €15-25 in FDM vs €40-80 in SLA.
Send us a photo or file via our quote form — we recommend the optimal process within 24h, at no consulting extra cost.
Read our FDM materials guide or request a personalized quote.
