PolyJet Clear (Rigid Transparent Photopolymer)

PolyJet clear materials are rigid, near-colorless acrylic photopolymers. Like the opaque rigid materials, they are jetted in very thin layers and cured immediately with UV light; VeroClear is a well-known example of the class. Parts come off the printer translucent and become transparent after wet sanding and polishing, or a clear coat. On multi-material printers, clear material can be combined with opaque, colored or rubber-like materials in one build, so internal components, colored markings and tinted transparent regions can be shown without assembly.

Choose PolyJet clear for visual and fit prototypes that must be see-through: housings that reveal a mechanism, light-pipe and lens mock-ups, flow visualization models, bottle and packaging concepts, and anatomical models with visible inner structures. Its mechanical limits are those of the rigid PolyJet family: it is brittle, softens at about 45–50 °C and ages under UV light. It is not an optical-grade material. Where light transmission, refractive accuracy or long-term clarity are specified, machined and polished PMMA or PC is the more reliable choice.

Mechanical and physical properties

Designing clear parts for PolyJet

Clear parts follow the general PolyJet rules: overhangs and cavities are built on a support material that is removed after printing, and very thin layers give fine detail and smooth surfaces. Transparency adds its own rules, because every face that touches support comes out frosted:

• Orientation for clarity: faces that must be clearest should face upward and be printed in glossy mode. Faces that touch support come out matte and need sanding and polishing before they become clear.
• Internal channels and cavities: support fills them during printing and leaves frosted inner walls that cannot be polished. Channels meant to show flow should be wide, short and open at both ends so support can be removed completely; expect a translucent rather than a glass-clear view.
• Wall thickness: walls of about 1 mm and up print reliably. Thicker sections look slightly tinted, while very thin walls are fragile during support removal and polishing.
• Polishable faces: large flat or gently curved faces are easiest to polish clear. Deep recesses, sharp inside corners and fine textures are hard to reach and stay hazy.
• Combined materials: opaque inserts, colored markings or rubber-like seals can be printed inside or onto a clear body in one build. Upload them as separate bodies or as a 3MF file so each region gets the right material.
• Fits and threads: leave clearance between mating parts, use inserts for threads that carry load, and validate fit-critical features on a prototype.

Getting a transparent finish

As printed, even glossy faces show a faint layer structure and a slight haze. Transparency comes from post-processing: wet sanding with progressively finer grit removes support marks and layer texture, and polishing or a clear coat then restores gloss. A clear coat is quicker on complex shapes and fills fine scratches; polishing keeps the bare material and suits flat faces. Freshly printed parts can show a faint yellow tint that usually fades under strong light after printing. Long UV exposure in service, however, yellows and embrittles the material.

Tolerances and surface

Without a tolerance on the drawing, Uretyco's default for PolyJet parts is ±0.2 mm or ±0.2%; tighter values apply only when they are stated on the drawing and accepted in the quote. Printed accuracy also depends on orientation, part size, support strategy and post-processing, and sanding and polishing for clarity remove a little material from the treated faces. Keep fit-critical faces out of the polishing scope or mark them on a drawing, and test critical fits on a prototype.

Finishing options

Finishing decides how transparent a clear PolyJet part becomes. Most of the work is manual, so specify which faces must be clear and which may stay frosted.

Cost and lead-time drivers

Clear PolyJet parts are priced like other PolyJet parts, plus the manual work that transparency requires:

• Part volume, bounding box, orientation, support material and machine time. Orienting clear faces upward can increase build height or support use, so clarity and cost sometimes pull in different directions.
• Polishing scope: the number and size of faces that must be transparent is often the largest cost after printing.
• Clear coating, tinting and combined materials add process steps; multi-material and full-color builds cost more than single-material prints.
• Lead time: printing small parts can be fast, while sanding, polishing and coating add time, especially on large or complex parts.

PolyJet clear vs. other transparent options

Choose PolyJet clear when transparency must be combined with internal detail, colors or other materials in a single print. For single-material clear prototypes, SLA clear resin is usually sufficient and costs less. When the part must transmit light reliably, survive heat or impact, or stay clear for years, machine it from PMMA or PC. For small series, a polished PolyJet or SLA master can serve as the pattern for clear cast polyurethane parts.

When not to choose PolyJet clear

Typical applications

• See-through housings and covers that show internal mechanisms or electronics.
• Light-pipe, lens and lamp-cover mock-ups for appearance and fit checks.
• Flow and mixing visualization models at low pressure and room temperature.
• Bottle, cap, packaging and cosmetics concepts.
• Anatomical and teaching models with colored inner structures.
• Master patterns for clear cast polyurethane parts.

Specifying PolyJet clear on Uretyco

1. 1
   Upload STL, 3MF or STEP

   Use 3MF or separate bodies when clear, colored and opaque regions are combined. Check units and mesh resolution, as faceting shows clearly on transparent faces.

2. 2
   Choose PolyJet and the clear material

   If a tint is needed, state the color; tinted transparent regions are confirmed in the quote.

3. 3
   Mark the transparent faces

   Show which faces must be clear, which may stay frosted, and from which direction the part will be viewed.

4. 4
   Choose the finish

   Polished, clear-coated or as printed; note faces and fits that must not be sanded or coated.

5. 5
   Describe the use and review the quote

   Tell the assistant whether the part is a visual model, a fit check, a flow model or a master pattern. Feasibility, finishing and lead time are confirmed in the quote and order review.

FAQ

How transparent are PolyJet clear parts?

As printed, they are translucent with a slight haze, and faces that touched support are frosted. After wet sanding and polishing, or a clear coat, flat and convex faces become clear enough to see internal components sharply. Thick sections keep a faint tint, and internal channels stay frosted.

PolyJet clear or SLA clear resin?

Both reach a similar clarity after polishing. SLA clear resin is usually cheaper for single-material parts. PolyJet is the better choice when the clear part needs colored or opaque internal features, rubber-like regions or several materials in one print.

Can PolyJet clear replace PMMA or PC lenses?

Only for appearance and fit mock-ups. The material has no specified optical properties, its clarity depends on finishing, and it ages under light and heat. Functional lenses, light guides and protective windows should be machined and polished from PMMA or PC, or molded for volume.

Do clear parts yellow over time?

Fresh parts can have a faint yellow tint that usually fades under strong light after printing. Over longer periods, UV light and heat age the material, so it can yellow and become more brittle. Keep display models out of direct sun; a UV-protective clear coat slows the effect but does not stop it.

Related resources

• PolyJet Rigid OpaqueOpaque and full-color PolyJet models.
• Clear Resin (SLA)Transparent SLA prototypes.
• PMMA (Acrylic)Machined, optically clear parts.
• Polycarbonate (PC)Tough transparent covers and guards.
• Cast PolyurethaneClear small series from printed masters.
• Surface FinishingSanding, polishing and coating options.