MJF vs SLS is one of the first questions buyers ask a bureau that runs powder-bed machines. A July 2026 r/3Dprinting thread put it plainly. An engineering team outsourcing functional parts asked whether MJF really is more isotropic than SLS, and whether the grey color is the only downside.
Are the parts really that different?
Often less than people expect. Formlabs, which sells SLS machines, notes that service bureaus often make no distinction between the two because the final part properties are largely similar. For one-off parts, it says, the difference is usually not important.
Where does MJF have the edge?
Operators who run both machines report that MJF is slightly more isotropic and has a smoother surface. One operator on r/AdditiveManufacturing favors MJF for density, air tightness, fine detail and interlocking parts. FacFox’s material data lists MJF PA12 with the same tensile strength in Z as in XY (48 MPa), compared with 42 MPa in Z for its SLS PA12.
Where does SLS win?
The same operators say SLS is somewhat more cost-effective, handles sharp details better, and has produced very long parts well, since MJF has a shorter build window. White SLS powder also makes it easier to dye parts other colors. On the downside, MJF can be harder to manage on heat with large or blocky parts.
How does cost compare for MJF vs SLS?
It depends on utilization. One analysis argues that MJF’s high fixed service cost and lower realistic packing density can raise cost per part unless the machine is kept full. Formlabs puts HP MJF systems at about $350,000 to more than $600,000. Don’t promise a blanket price advantage either way.
How should you answer the customer?
- Start with requirements: color, sealing, detail, part length, budget.
- Recommend a process for this part, not in general.
- Show both options with price and lead time side by side when you can.
An instant quote that prices each process and material from the same upload makes that comparison easy for the customer. If your quoting tool can show MJF and SLS options side by side, use it; if not, send both prices in the same reply.
Related on the Solvi blog: PA11 vs PA12 on MJF: When Is PA11 Worth Running?; Should You Dye MJF Parts Black or Vapor Smooth Them?; MJF Packing Density: How Full Should You Pack a Build?.
Sources: r/3Dprinting thread; r/AdditiveManufacturing thread; Formlabs MJF vs SLS comparison; FacFox nylon guide; Rare Kolesar cost analysis.