Can you 3D print transparent parts?
Yes, but not with every technology. FDM lays molten filament in beads side by side; the seams and trapped air scatter light, so an FDM print is cloudy at best. Powder processes such as SLS and MJF always give an opaque, grainy surface.
SLA works differently: the resin cures into a solid, closed material with no seams between beads. With Clear Resin that gives you a part you can genuinely see through. That's why SLA with Clear Resin is the standard choice for transparent prototypes.
Translucent or clear: what can you achieve?
After printing, washing and post-curing, a Clear Resin part has fine layer lines and small support marks. These scatter light: you see shapes and colours through the part, but not sharply. That's what we call translucent. For many uses, such as a light guide or a cover where you only need to see an LED, that's already enough.
If you want to see clearly through it, finishing is needed. There are two common routes:
- Sanding and polishing: the surface is sanded progressively finer, then polished to a shine. The result approaches glass, provided the surface can be reached.
- Sanding and clear lacquer: after sanding, a clear coat fills the fine scratches. This also works well on larger or gently curved faces.
We do this finishing in-house. Bear in mind it takes more handwork than a standard print, which raises the price. You'll see it listed separately in the quote.
Overview: from raw to clear
| Finish | Result | Suited to |
|---|---|---|
| As printed | Translucent, slightly matt | Light guides, LED covers, internal checks |
| Sanded | Even matt, satin-like | Diffusers, frosted-glass look |
| Sanded and polished | Clear on the worked faces | Viewing windows, fluid visibility |
| Sanded and lacquered | Clear, glossy | Show models, presentations |
Design tips for transparent parts
- Keep the faces you want to look through flat or gently curved and easy to reach: internal channels and deep cavities can't be polished and stay translucent.
- Tell us which side is the show face. We then orient the part so the supports end up on the other side.
- Thinner walls are clearer than thick blocks. A solid chunk may show a slight tint.
- Avoid sharp internal corners on show faces; they're hard to sand.
- Clear Resin is a standard resin: stiff and rather brittle. Don't plan snap-fits or parts that must absorb impacts.
- Clear resin can yellow slightly over time under prolonged strong sunlight. For a prototype or show model that's rarely an issue.
Applications of transparent 3D printing
- Light guides and covers: carrying light from an LED to the front of a housing, or making an indicator visible.
- Fluid visibility: a reservoir, manifold or flow model where you can see liquid or air moving.
- Show models: a see-through housing that reveals a product's inner workings, for trade fairs, presentations or internal reviews.
- Fit checks: through a transparent housing you can see whether cables, boards and components fit properly inside.
- Prototypes of covers and windows that will later be moulded or cast in a clear plastic.
Clear Resin isn't optical glass. For lenses with optical precision or parts that will stay outdoors for a long time, talk the application through with us first.
And for larger quantities?
Clear Resin is ideal for one or a few parts. If you need dozens of transparent parts, vacuum casting in clear polyurethane can be an alternative: a finished SLA print then serves as the master for a silicone mould. Vacuum casting is done through selected partners; you request a quote and get an answer within one working day.
What does a transparent 3D print cost?
SLA starts from €0.20/cm³; Clear Resin costs from €0.50/cm³, excl. VAT and excl. finishing. Sanding, polishing or lacquering come on top and depend on the number of show faces and how clear it needs to be.
Worked example
A transparent cover with a volume of 40 cm³ in Clear Resin: 40 cm³ × €0.50/cm³ = from €20.00 per part, excl. VAT and finishing. Volume times material price is a starting point; your actual price is shown in Quotebase.