PolyJet

PolyJet 3D printing jets and UV-cures photopolymers to produce smooth, highly detailed multi-material plastic parts with fine features and excellent surface finish.

Overview

PolyJet, also known as material jetting, builds parts by jetting tiny droplets of liquid photopolymer and curing them with UV light layer by layer. It delivers very smooth surfaces, fine feature resolution, and the ability to combine multiple materials and colors in a single print, including rigid, flexible, and transparent zones in one part.

PolyJet fits best for appearance models, ergonomic mockups, microfluidic features, and complex soft-over-hard geometries where surface quality and detail matter more than long-term mechanical strength. It excels at simulating overmolds, gaskets, buttons, and clear windows in a single build. Tradeoffs: parts are made from UV-cured photopolymers, not engineering thermoplastics, so they have lower temperature resistance, can creep under load, and may change properties over time. It’s not ideal for functional end-use parts in harsh environments or for very large, structural components, but it’s a strong choice for high-fidelity prototypes and complex multi-material concepts.

Common Materials

  • Rigid photopolymer resin
  • Digital ABS
  • Transparent photopolymer
  • Elastomer-like photopolymer
  • High-temperature photopolymer

Tolerances

±0.004" to ±0.008"

Applications

  • High-detail visual prototypes and show models
  • Overmold and soft-touch interface simulations
  • Microfluidic and small manifold prototypes
  • Medical and dental models and surgical guides
  • Consumer product housings with clear windows
  • Flexible seals, gaskets, and buttons for fit/feel testing

When to Choose PolyJet

Choose PolyJet when you need very smooth surface finish, small features, and realistic multi-material or color prototypes in short lead times. It’s ideal for design validation, ergonomic studies, and complex soft-over-hard geometries where visual quality and tactile feel are more important than structural performance or long-term durability. Volumes are typically single parts to short prototype runs.

vs Fused Deposition Modeling (FDM)

Pick PolyJet over FDM when you need finer details, smoother surfaces, and accurate thin walls or intricate channels. Use it for appearance models and multi-material prototypes where FDM’s layer lines, lower detail, and single-material limitation would mask design intent or require heavy post-processing.

vs Stereolithography (SLA)

Choose PolyJet over SLA when you need multi-material parts, variable durometers, or full-color and clear plus opaque features in one build. For complex assemblies that benefit from integrated soft seals, overmolds, or transparent windows, PolyJet offers more material flexibility and faster iteration than single-resin SLA.

vs Selective Laser Sintering (SLS)

Use PolyJet instead of SLS when visual quality, surface smoothness, and sharp detail matter more than mechanical robustness and temperature resistance. For show models, ergonomic mockups, or fluid channels that must be smooth and easily inspected, PolyJet’s surfaces and translucency outperform the grainy, porous texture typical of SLS parts.

vs Multi Jet Fusion (MJF)

Select PolyJet when you need cosmetic-quality surfaces, transparent elements, or soft-touch regions rather than tough, production-like nylon parts. For design reviews, marketing samples, and assemblies with built-in gaskets or buttons, PolyJet gives better appearance and material variety than the monochrome, structural parts typical of MJF.

vs Digital Light Processing (DLP)

Choose PolyJet over DLP when your part needs multiple materials, gradients in stiffness, or color zones in a single build. For complex prototypes with soft-over-hard regions, clear windows, and smooth organic shapes, PolyJet offers more material combinations and typically larger build formats than most DLP systems.

Design Considerations

  • Maintain minimum wall thickness of 0.6–1.0 mm for rigid regions and thicker for flexible sections to avoid warping and tearing during support removal
  • Add generous fillets and transitions between rigid and flexible zones to reduce stress concentrations and improve durability of multi-material interfaces
  • Design drain holes and access openings so support material can be flushed from internal cavities, channels, and undercuts
  • Orient parts to prioritize critical cosmetic surfaces and fine details away from heavy support contact for better finish and easier cleanup
  • Avoid extremely thin pins, living hinges, or snap-fits intended for repeated use; validate critical features with clearance and strength tests or secondary machining
  • Specify only necessary tight tolerances and critical datum features so the shop can orient and process parts efficiently and quote realistically