A part printed in filament is almost never transparent like glass: every line and every layer scatters the light. What you can get is a highly translucent part, useful for lamps, diffusers, box windows or decorative pieces. The result depends on the material and, above all, on how you print.
Which transparent filament is the clearest
Copolyesters and polycarbonate are the naturally clearest materials. Clear PLA is really PLA with very little pigment: translucent, but hazier.
Medians from each material's datasheets. Click a material to see its full range.
- PETG: the most balanced option. Easy to print and with good clarity in natural versions.
- PCTG: even clearer and tougher than PETG, printed the same way.
- Polycarbonate: very clear and heat-resistant, but demanding on the printer.
- PVB: it smooths with isopropyl alcohol and ends up glossy and very translucent.
Print settings for transparent parts
- 100% infill in parallel lines: any air gap makes the part opaque.
- Tall layers and generous extrusion widths, so there are fewer boundaries between lines.
- Temperature at the high end of the range and low speed, so the lines fuse into each other.
- Low fan, so the plastic cools slowly.
- Very dry filament: moisture creates microbubbles that turn the part white.
How to improve clarity after printing
Sanding with ever finer grits and applying a varnish or a clear resin fills the layer marks and greatly increases clarity. With PVB, smoothing with alcohol vapor gives a similar effect without sanding.
Frequently asked questions about clear filament
Is there a fully transparent filament?
The material on the spool can be, but the printed part never comes out like glass because of the layers. With PETG, PCTG or polycarbonate and the right settings you can get highly translucent parts.
Why do my transparent prints come out white?
Because of air trapped between lines, partial infill or moisture in the filament. Print with full infill, a higher temperature, a lower speed and dry filament.