Diffusive Filament Test

These prints are designed to test how good filament diffuses light, in case you're looking for filament suited for printing LED diffusors.
This project highly DEPENDS ON YOU to add makes with different filaments!

Please pay attention to the print settings!

I do have filament which is really good at diffusion light. However, it is not sold anymore and I'm running out of it... I looked for replacements, but all others I've found so far suck at diffusing light properly. This is why I need your help - and if you design 3D prints that need light diffusion, you may also benefit from this project

I've designed three simple prints that show how good filament diffuses light.
The two ramps are used to show how light is diffused with distance and also by the thickness of the prints. One is printed flat consisting of infill, one is printed standing, consisting of perimeters.
The flat one features four ramps with different thicknesses of 0.2mm/0.4mm/0.6mm/0.8mm.
The standing one is 1mm thick (2 perimeters).
The cylinder is designed to be put upside down on a standard 5050 RGB LED (e.g. WS2812B / SK6812 / NeoPixel).

Ramps

As you see on the picture with the ramps, the left filament partially blocks light (text gets harder to see on thicker ramps) but it doesn't diffuse (text is almost the same visibility along the ramp).
The filament on the right actually blocks less light (text is darker on the bottom edge) but it also diffuses the light (text gets harder to read along the ramp to the top edge).

Cylinder

It's hard to capture the effect on a cheap smartphone cam, but you can still see the difference.
The filament on the left almost only refracts the light, resulting in sharp glare light-bars being visible through the side and also being able to see the sharp outline of the LED through the top. The refraction also causes the light to split apart. You can clearly see distinct red and green spots - it's not white at all.
On the right the same amount of light gets passed, but it's not refracted. The visible outline of the LED is less sharp and the light is almost perfectly white (hard to see on the picture)

good ones:

• Kexcelled K5 PETG "Transparent White" / "Clear White" (NOT "Diffuse Clear White"!)
• RepRapper Natural PLA (bought 2014 on amazon.de via KaufKlub, not available) (right one in picture)

most promising:

• colorFabb Milky White (colorfabb.com) (not seen in person yet, but colorFabb provided photos, see above)

not that bad:

• Kexcelled PETGk5-diffuse: light diffuse PETG (bought 2020 on ruhr3d.shop) (pretty clear)

bad ones:

• RepRapper Natural PLA (bought 2019 on reprappertech.com) (left one in picture)
• DasFilament Natur F10108 PLA (bought 2018 on dasfilament.de) (crystal clear)
• DasFilament Weiß F10101 PLA (bought 2018 on dasfilament.de) (too opaque)
• TechnologyOutlet Natural PLA (bought 2019 on amazon.de) (identical to RepRapper 2019)
• GOEDIS Transparent PLA (bought 2019 on goedis.de) (clear)
• Redline Filament Natur/Transparent PLA (supplied by redline 2019) (clear)
• Redline Filament Neon Transparent PLA (supplied by redline 2019) (clear)

not yet tested:

• AMOLEN PETG Light Transmission Filament (amazon)
• PLA Filament Litho Weiß (azurefilm.de)