The short comparison
| SLS | MJF | SLA | |
|---|---|---|---|
| How it works | A laser sinters nylon powder layer by layer | Inkjet agents plus an infrared lamp fuse powder | Light cures liquid resin layer by layer |
| Supports | None; loose powder holds the part | None | Needed; they leave small marks |
| Common materials | Nylon 12, Nylon 11, filled nylons, TPU | Nylon 12, Nylon 11, TPU, PP | Standard, tough, flexible, rigid and clear resins |
| Surface | Matte, slightly grainy; smooths well | Matte, grainy, gray-black | Smooth, very fine detail |
| Best at | Functional parts, snap fits, small batches | Large batches of nylon parts | Detailed, clear or rubber-like parts |
When SLS is the right call
SLS parts are printed inside a bed of powder, so overhangs, internal channels and interlocking assemblies need no supports. Nylon 12 and carbon fiber Nylon 11 handle impacts, heat and repeated snap-fit cycles that would crack most resins.
Packing matters for price. Formlabs says its Fuse 1+ can pack builds up to 26% by volume, against the 10 to 12% it cites as the recommended limit for HP's compact MJF printer. Those are a vendor's own figures, but they explain why SLS services can price small batches aggressively.
When MJF makes sense
MJF machines are built for throughput: big bureaus run fleets of them for hundreds or thousands of identical nylon parts. If you need 2,000 clips next month, an MJF bureau may beat a smaller SLS shop on unit price. For 1 to 100 parts with fast turnaround, SLS is usually as good or better.
When SLA wins
Resin printing on a Formlabs Form 4 gives the sharpest detail and the smoothest surface of the three. It is the only one here that prints clear parts, rubber-like parts such as Flexible 80A, and polypropylene-like snap fits in Tough 1500 with fine features. Supports leave small marks, so tell us which faces must be clean.
Picking a material on our quote page
- Strong part, complex shape, or anything that sees heat: Nylon 12, or Nylon 11 CF for stiffness.
- Fine detail, clips and living hinges: Tough 1500 Resin.
- Gaskets, grips and bumpers: Flexible 80A Resin.
Upload once and switch materials on the quote page; the price and ship date update for each.