Not all 3D printing is created equal. The three most common technologies — FDM, SLA, and SLS — each have distinct characteristics that make them better suited for different applications. Here's how to decide which one you need.
FDM (Fused Deposition Modeling)
FDM is what most people picture when they think of 3D printing. A heated nozzle extrudes melted plastic filament layer by layer to build up the part.
Strengths: Affordable, wide material selection (PLA, PETG, ABS, TPU, nylon, carbon fiber composites), large build volumes, good for functional parts and prototypes.
Weaknesses: Visible layer lines, limited detail on small features, support removal can leave marks.
Best for: Functional prototypes, mechanical parts, large prints, enclosures, jigs and fixtures.
Cost range on 3D Tri: $0.10-0.25 per gram.
SLA/DLP (Stereolithography / Digital Light Processing)
Resin printing uses UV light to cure liquid photopolymer resin layer by layer. SLA uses a laser while DLP uses a projected image — both produce similar results.
Strengths: Exceptional surface finish, incredible detail (down to 25-50 microns), smooth surfaces require minimal post-processing.
Weaknesses: More expensive materials, smaller build volumes, parts can be brittle, post-processing requires washing and curing, resin is messy and potentially irritating.
Best for: Miniatures and figurines, jewelry patterns, dental models, precision engineering, any application where surface finish and detail matter.
Cost range on 3D Tri: $0.20-0.60 per gram.
SLS (Selective Laser Sintering)
SLS uses a laser to fuse powdered material (typically nylon) into solid parts. The unsintered powder acts as its own support structure, enabling complex geometries.
Strengths: No support structures needed, excellent mechanical properties, can produce complex interlocking assemblies, near-isotropic strength.
Weaknesses: Expensive machines (though some desktop options are emerging), grainy surface texture, limited material options, requires significant post-processing.
Best for: Production parts, complex geometries with internal channels, moving assemblies, high-performance applications.
Cost range on 3D Tri: $0.40-1.00+ per gram.
Making Your Decision
When submitting a project on 3D Tri, consider what matters most: need high detail? Go SLA. Need strength and low cost? Go FDM. Need complex geometry without supports? Go SLS.
Not sure? Just describe your project to the community. Triangle makers are happy to recommend the best technology for your specific application. That's the beauty of a local network — you get expert advice along with your prints.