Test guide · Updated September 2026
Filament transparency tests explained
A filament transparency card shows how the same material transmits light at several printed thicknesses. It is useful for translucent parts, lamps, lithophanes and any design where the colour changes with wall thickness.
What the six windows measure
The Free 3D Samples model uses six recessed windows with controlled floor thicknesses:
| Window | Floor thickness | What it helps compare |
|---|---|---|
| 1 | 0.2 mm | Single-layer appearance |
| 2 | 0.4 mm | Very thin walls |
| 3 | 0.6 mm | Increasing colour density |
| 4 | 0.8 mm | Thin functional walls |
| 5 | 1.0 mm | Near-opaque transition |
| 6 | 1.5 mm | Thicker-wall appearance |
Transparency is not controlled by thickness alone
Layer height, extrusion consistency, temperature, cooling, infill, surface texture and filament moisture can all change the result. A transparency swatch is therefore a comparative tool rather than a universal optical measurement.
How to run a repeatable comparison
- Generate and label a card for the filament under test.
- Use the same nozzle, layer height and slicer profile for each material you want to compare.
- Place every finished card in front of the same diffuse light source.
- View or photograph the cards from the same angle and distance.
- Record any changed print settings on the card or in your filament catalogue.
Transparent versus translucent filament
A filament sold as clear or transparent will not necessarily produce glass-like FDM parts. Interfaces between extrusion lines and layers scatter light. The card is valuable because it shows the result produced by your actual filament, machine and settings instead of relying on a product photograph.
Generate a transparency test STL
Customize the brand, colour, material and optional ironing settings, then inspect the model before printing.
Create a transparency card