§ 01 / WHEN

When MJF beats SLS

HP Multi Jet Fusion and SLS look similar on the surface — both print nylon in a powder bed. The differences matter for production:

Tolerance. MJF holds ±0.2 mm routinely; SLS is ±0.3 mm. For press-fit features or precision assemblies, MJF is the better choice.

Speed. MJF's area-based fusing (vs. SLS point-laser) is 3-5× faster per build. That translates to tighter lead times and lower per-part cost at scale.

Consistency. MJF's process produces more uniform mechanical properties along X, Y, and Z axes than SLS. Parts are closer to isotropic.

Aesthetic. MJF parts come out uniform dark gray. SLS parts are natural cream/white that need post-dyeing for uniform color. For consumer products where appearance matters, MJF skips a step.

Where SLS wins: material variety. MJF runs PA12, PA12-GB (glass-bead), PA11, and PP. SLS runs those plus flexible TPU, flame-retardant, and carbon-filled variants.

§ 02 / MJF

MJF materials we stock

Material	Best for	Tensile	Elongation	HDT
PA12 (HP 3D HR PA12)	General production, default choice	48 MPa	20%	175 °C
PA12-GB (Glass bead)	Higher stiffness, dimensionally stable	30 MPa	6%	172 °C
PA11	Impact + ductility, bio-based	48 MPa	50%	182 °C
PP (Polypropylene)	Chemical resistance, low cost	30 MPa	20%	100 °C
TPU (Estane 3D)	Flexible parts, shock absorption	9 MPa	300%	—

§ 03 / APPLICATIONS

Applications

Production end-use parts500–10,000 unit runs. Per-part cost competitive with injection molding at low volumes.

Custom grips & handlesPersonalized fit, textured surfaces, brand colors — batch per-order.

Orthopedic bracesPatient-specific geometries from 3D body scans. Single-piece, no assembly.

Automotive interiorClips, brackets, mounts, and interior trim in PP for chemical resistance.

Industrial toolingFixtures, jigs, end-effectors. Glass-bead PA12 for stiffness.

Consumer electronicsEnclosures with integrated features that would require complex molds in injection molding.

§ 04 / MJF

MJF design guidelines

Wall thickness ≥ 0.8 mm

Minimum reliable wall. 1.0 mm for larger parts to survive powder extraction.

Holes print slightly under

Expect horizontal Ø10 mm holes to print at 9.8 mm. For press-fits, either design oversize or ream post-print.

Nest for cost efficiency

Every build is expensive whether full or empty. We batch small parts from multiple customers to amortize build cost — tell us if your timeline allows batching (usually saves 20–30%).

Fine text must be embossed, not engraved

Engraved text (recessed) below 1 mm may fuse closed. Embossed (raised) text stays crisp down to 0.5 mm line width.

Color is uniform dark gray

MJF parts are inherently ~80% gray from the fusing agent. Can be dyed (typically black) for uniform through-color, but cannot be dyed lighter than the base gray.

§ 05 / FAQ

FAQ

What's the break-even point with injection molding?

Typically around 2,000–5,000 parts for small- to mid-size geometries. Below that, MJF wins. Above, injection molding wins even with tooling cost. Complex geometries that would need expensive molds (sliders, multi-piece cores) push the break-even higher — sometimes MJF stays cheaper even at 10,000 units.

How does MJF compare to FDM for production?

MJF is nearly always better for production: better tolerance, better mechanical properties, no support scars, much better surface finish. FDM wins only on prototyping cost for single parts ($15 vs $50 typical) and on build volume flexibility.

Can MJF parts be painted?

Yes — standard primers (sandable), lacquers, and acrylic paints all adhere well. Light sanding with 400-grit before painting improves adhesion. We can dye, paint, or leave natural per your spec.

Do you provide quality documentation for production runs?

Yes. For orders above 100 units we include FAI report, dimensional inspection of 3 random parts, and material COA. For medical/aerospace, full ISO 13485 or AS9100D documentation available.

MJF — HP Multi Jet Fusion for tighter-tolerance nylon production.