This first piece has a lot of experiments built in: How does thickness affect the amount of light transmitted, how does thinning the front, back or both affect the look, can I "trap" the light in the thinned areas, and how do two lights show up within one thinned recess?
I learned a lot on this first iteration. I won't bore you with the details, but I will note that the difference between a nice glow, a stringy mess and nearly opaque can be a matter of 0.01 mm. That's a pretty tight tolerance.
As you can see below, even at night, the thicker areas block the light quickly.
I will need to try out other filaments to see if they give me more latitude in thicknesses while maintaining the diffuse look.
You might have noticed the curving incised lines. They are very deeply cut, so they transmit more of the light. I wanted to see what they looked like. I had hoped they would create a gradient as they carried the colored light from multiple LEDs. It kind of works.
But there was also a second reason for them. I wanted to try embedding wire in them, then pour enamel paint (okay, cheap nail polish - same thing) in between the wires like a cheap, faux cloisonné.
I did a first, tentative experiment with the nail polish. I selected different colors, styles and brands to see how they affected the light. I did not select the colors for a pleasing composition - and boy, did it turn out ugly in the daylight.
But the nail polish does affect the quality of the transmitted light. Once again, the results didn't adhere to my predictions. Chalky does not block more light and sparkly daylight posihs does not sparkle at night, even when lit.
The thickness of the nail polish does affect how much light gets through. But I was happy to see that almost all the paint can be applied thickly with no significant negative affects. That's great, because I really want to just pour the paint into the recesses and not have to struggle to get an even coat with a brush.
All in all, I'm very happy with this first try. Expect to see more about this technique in the near future.
I used the Circuit Playground board from Adafruit - get it at Amazon.