Choose SLS as soon as you need mechanical strength, toughness or higher temperature resistance. SLS PA12 hits 45 MPa, isotropic and tough. SLA resin is usually more brittle (10-70 MPa depending on resin), UV-sensitive and less tough. SLA wins on aesthetics: smoother surfaces straight out of the printer, detail below 0.1 mm.
Where SLS wins
SLS parts are functional workpieces. You can screw, click, flex (PA11 to 31% elongation) and load them long-term without cracks.
SLA parts are typically brittle: they break on impact, discolour under UV, weaken in the sun or at raised temperature. Fine for a prototype you show to a customer. Not for parts that are actually used or must run in production.
Where SLA wins
For very fine detail reproduction (scale models, jewellery, dental applications, aesthetic design elements) SLA is superior. Surface quality straight from the printer approaches injection moulding.
If your priority is visual and the part is not mechanically loaded, SLA is often the better choice at a specialised partner. We focus on SLS because it is functional; for aesthetic SLA we refer you.
Decision tree
Ask yourself: does the part get used, or only viewed? Does it have to fit in an assembly or take load? Must it resist temperature, UV or chemicals? “Yes” on any of these: SLS.
Are you looking for a photo shoot model, a detail-accurate prototype or a fine inspection handle? SLA. On the fence? An SLS print with vibratory polish is often enough for aesthetic requirements and keeps all mechanical advantages.