Overview
- Multi Jet Fusion (MJF) is an industrial 3D printing technology by HP that produces strong, isotropic nylon parts with fine feature resolution and no support structures. Parts are fully dense and watertight straight out of the machine, making MJF an excellent choice for functional prototypes, end-use components, and high-volume production runs alike.
- MJF is especially well-suited for complex geometries — internal channels, undercuts, and enclosed features that other technologies can't handle — and it scales efficiently, with hundreds of parts nestable in a single build at competitive per-part cost.
- No setup work needed on your end. When submitting an MJF request, there is no need to specify build orientation or nesting strategy. Our Tech Foundry staff will configure the build to maximize density and minimize cost. The technical details below are provided for your reference.
Applications
MJF is well-suited for any application requiring durable nylon parts with fine features, production-like quality, or high part counts per build:
- Functional prototypes requiring strength and stiffness
- Complex geometries with internal channels or undercuts
- Fluid-handling components (watertight as-printed)
- Housings and enclosures with IP-rated sealing potential
- Automotive interior components and under-hood
parts
- Color-coded assemblies and labeled components (HP 580)
- End-use production parts and short-run manufacturing
- Snap-fits, living hinges, and flexible features
- Custom orthotics, prosthetic sockets, and wearables
- Dental, surgical planning, and medical device models
- High-volume batches (100–300+ parts per build)
- Anatomical models and consumer product mockups (HP 580)
Tech Foundry Hardware
HP Jet Fusion 5200
Build Volume: 380 × 284 × 380 mm (14.96 × 11.18 × 14.96 in.)
Layer Thickness: 0.08 mm (80 µm)
Dimensional Accuracy: ±0.3% (minimum ±0.3 mm)
Minimum Feature Size: ~0.5 mm
In-Stock Materials: HP 3D HR PA12 (nylon)
Surface Finish: Matte gray (as-printed); dyeable black, blue, or other colors
Units: 1
Location(s): Aggie Square (Sacramento)
Unique Properties:
- Large build volume, automated powder management, and high throughput make this the go-to system for volume manufacturing, functional parts, and complex geometries in PA12 nylon.
HP Jet Fusion 580 Color
Build Volume: 332 × 190 × 248 mm (13.1 × 7.5 × 9.8 in.)
Layer Thickness: 0.08 mm (80 µm)
Dimensional Accuracy: ±0.3% (minimum ±0.3 mm)
Color Capability: Up to 10 million colors, printed directly into part surface
In-Stock Materials: HP 3D HR CB PA12 (color-bindable nylon)
Surface Finish: Matte; full color as-printed
Units: 1
Location(s): Aggie Square (Sacramento)
Unique Properties:
- The HP 580 is our solution for full-color MJF printing. Unlike the 5200 (which produces dark gray parts dyeable to a limited palette), the 580 can reproduce millions of colors directly in-part. If color accuracy or multi-color is a priority, specify the 580 in your service request or ask our staff.
Materials
HP 5200:
HP 3D HR PA12 · Nylon 12
The workhorse MJF material. Offers an excellent balance of tensile strength (~48 MPa), impact resistance, chemical resistance, and flexibility. Biocompatible. Ideal for functional prototypes, housings, brackets, and end-use components. Parts emerge in a characteristic dark gray and can be dyed black, blue, or other colors in post-processing.
HP 580:
HP 3D HR CB PA12 · Color-Bindable Nylon 12
A specially formulated PA12 that accepts color binding agents during the print process, enabling full-color part surfaces in millions of colors. Mechanical properties are similar to standard PA12. Used exclusively in the HP Jet Fusion 580 for color-critical applications.
Comparison to Other Printing Technologies
Contrasted with FDM
MJF parts are isotropic — consistent mechanical properties in all three axes — unlike FDM parts, which are weaker in the Z-direction. MJF also eliminates layer lines and requires no support structures, yielding smoother surfaces and enabling fully enclosed internal features. For structural applications requiring repeatable nylon parts, MJF is considerably superior to standard FDM.
Contrasted with SLA/MSLA
MJF produces tougher, more impact-resistant parts than most photopolymer resins. While SLA can offer greater detail at very small scales, MJF PA12 provides superior long-term durability, UV stability, and chemical resistance for functional end-use parts.
Contrasted with PolyJet
PolyJet excels at multi-material and full-color capability with extreme dimensional precision, but produces parts that are significantly weaker and more brittle than MJF nylon. MJF is the preferred choice when mechanical performance and production economics are the priority. For full-color MJF specifically, the HP 580 now offers a strong alternative to PolyJet for color-critical applications that also need nylon-class strength. PolyJet remains better suited for transparent or rubber-like material requirements.
Contrasted with Reinforced FDM
When maximum strength is required — particularly for structural or load-bearing applications — our Markforged reinforced FDM system (continuous carbon fiber) can exceed MJF in mechanical performance. However, MJF offers broader design freedom, finer feature resolution, and better economics for production volumes.
Examples:
MJF Printing Gallery
Click here to view more example MJF prints.
Rates
- Note: We strongly recommend submitting a service request to obtain an accurate project cost estimate. Self-quoting can often lead to miscalculations
- Already have a quote from another vendor? Share it with us and we'll match or beat it.
We bill for time and materials while using our MJF printers. For time, we assess 0.5 hours of assisted time per-print tray plus an hourly rate for machine use. Maximizing build tray capacity with your parts—whether identical or varied—significantly reduces per-unit part cost.
| Description | Internal | External | |
| Materials | Per-gram expense for all materials in-stock | $0.60/g | $0.80/g |
| Setup and Processing | 0.5 hours of our assisted rate ($119/hour) per build (not object) | $119/build | $160/build |
| Hourly Use Rate | Expense per hour of machine use | $11/hour | $14/hour |
Estimating project cost should be left to the Tech Foundry, but here are some general project estimates that can guide in self-estimating:
| Relative Project Scale | Cost for First Batch of Parts, Typical Range | Cost for Additional Batch of Parts, Typical Range |
| Small | $120 | $15-$30 |
| Medium | $120-$200 | $30-$150 |
| Large | $200-$500 | $150-$350 |
| Extra Large | $500+ | $350+ |
*All declared values at internal rates, NUD = university required "Non-University Differential" added for external.
Optional Post-Processing Services
MJF parts are functional as-printed, but finishing can improve appearance, feel, and performance for end-use applications. Our available finishing services are listed below.
Impact Polishing — Form Labs Fuse Blast
Process: Automated tumble-blasting with polishing media
Surface Result: Smooth, semi-gloss, scuff-resistant finish
Compatible Materials: PA12 (Nylon 12)
Typical Cycle Time: 15–50 minutes
Units: 1
Location(s): Aggie Square (Sacramento)
What it does:
- The Fuse Blast is an automated machine that cleans and polishes MJF parts in a single step. Parts are tumbled in a basket while a stream of small polishing beads compacts the surface — similar in concept to how a rock tumbler smooths stones. Unlike sanding or chemical treatments, this process does not remove material or alter the part's geometry. The result is a noticeably smoother, more finished-looking surface compared to the matte, slightly grainy as-printed finish. Parts come out clean, dust-free, and ready for dyeing or use.
- Good for: Consumer-facing parts, display models, parts that will be handled frequently, or anything where a more polished look matters.
Vapor Smoothing — AMT PostPro SFX
Process: Automated chemical vapor smoothing
Surface Result: Glossy, sealed, near-injection-molded finish
Compatible Materials: PA12 (Nylon 12); PA11, TPU, and PP also supported
Typical Cycle Time: 90–120 minutes
Units: 1
Location(s): Aggie Square (Sacramento)
What it does:
- The PostPro SFX uses a controlled, non-toxic chemical vapor to gently reflow the outermost surface of a printed part. Think of it like applying very precise, even heat to slightly melt and re-solidify just the surface layer — smoothing out the texture without affecting the part's shape or internal structure. The result is a glossy, sealed finish comparable to injection-molded plastic. This process also improves the part's resistance to moisture and slightly enhances its mechanical toughness. It is the only finishing method that can reach internal channels and enclosed cavities, making it especially valuable for fluid-handling parts and medical models.
- Good for: Fluid-handling components, medical models, end-use consumer parts, or any application where a smooth, professional-grade surface is required.
Additional finishing options include:
- Dyeing — black, blue, or custom colors for improved aesthetics.
- Inserts & tapping — threaded inserts and secondary machining are fully compatible with PA12.
- Color printing (HP 580) — full-color surface finish, no secondary processing needed.
Preparing Files for Printing:
The Tech Foundry team suggests two sets of files for each 3D printed part (where possible) – the original parametric model file (Solidworks/Inventor/Fusion360/etc), and a millimeter scale STL file (point-mesh file). Please include these files on your project request if possible.
For multi-material prints, we require one STL file for each material in a shared coordinate system. Please work with Tech Foundry staff to ensure this constraint is satisfied.
Technical Details
This section is intended for technical reference. If you're not sure whether these details apply to your project, our team is happy to advise.
Multi Jet Fusion is a voxel-based powder bed fusion process. Each layer begins with a uniform spread of PA12 powder across the build platform. A printhead then selectively jets a fusing agent onto regions that should solidify, while a detailing agent is applied at boundaries to improve edge sharpness. An infrared energy array sweeps across the bed, causing only the fused regions to melt and bond. This cycle repeats at 80 µm per layer until the build is complete.
Because parts are fully surrounded by unfused powder throughout the build, no support structures are required — the powder itself provides support. This enables complex overhangs, internal channels, interlocking features, and fully enclosed cavities that are inaccessible in extrusion-based or resin-based printing workflows.
Parts emerge embedded in a powder cake and are excavated, then tumbled or media blasted to remove residual powder. Unfused powder is collected, blended with a proportion of fresh powder, and reused in subsequent builds — up to 80% reusability per cycle, making MJF one of the most material-efficient additive processes available.
The resulting parts are isotropic: mechanical properties are consistent in X, Y, and Z axes, unlike FDM where Z-axis strength is considerably lower. Surface finish is matte and slightly granular as-printed; secondary finishing (dyeing, media blasting, or vapor smoothing) can significantly improve aesthetics.
General Design Guidelines for MJF 3D Printing:
- Minimum Wall Thickness: Maintain walls of at least 0.5 mm; 1.0 mm or greater is recommended for structural features to ensure consistent fusion and part integrity.
- Minimum Feature Size: Features smaller than 0.5 mm may not resolve reliably. Pins, holes, and slots should exceed this threshold wherever possible.
- Clearance for Moving Parts: Allow a minimum of 0.5 mm clearance between interlocking or moving parts printed in assembly — MJF can print functional hinges and assemblies in a single build.
- Avoid Large Solid Volumes: Thick solid sections retain heat longer during cooling and can cause dimensional deviation or surface pitting. Consider hollowing large volumes with a wall thickness of 2–3 mm and an escape hole for powder removal.
- Escape Holes for Hollow Parts: Any fully enclosed hollow cavity requires at least one opening (≥ 5 mm diameter) so unfused internal powder can be removed after printing.
- Text and Surface Detail: Embossed or debossed text should be at least 0.5 mm deep/tall and 1.0 mm wide for reliable resolution.
- Color (HP 580 only): Color penetrates only the surface of the part (~0.5 mm). Parts intended for full-color use should not be designed to be machined, sanded, or finished post-print, as the color layer will be removed.
Get Started
- Heard enough? Get started with a service request! Your request need-not be perfect, we can always revise it as we go. Just provide us with as much detail as is necessary.
- Feeling overwhelmed with the options? We don't blame you! We do a lot! Feel free to email us to set up a consultation. We're happy to chat via zoom, or in person (where we can review samples).