I'm using a 2" cabochon made from epoxy resin colored with alcohol inks and mica powder as the face of my necklace. The secret to getting good diffusion is to use white mica powder stirred into the resin. The white mica powder lets the light diffuse through. Swirling it into the tinted resin makes for a beautiful necklace even when your NeoPixels are turned off.
I did a lot of experimenting to find a diffusion formula I liked. I thought the gold mica powders would look fabulous, but they just didn't work as a diffuser - they blocked the light entirely.
The epoxy resin pour is beyond the scope of this guide, but I've made a blog post with product links and tips and tricks. Check it out!
For my necklace, I used hot glue to secure everything to the back of the resin cabochon. I started by gluing down the NeoPixel Jewel, then arranged the components as neatly as possible on top.
I want the USB port on the ItsyBitsy to be accessible - this is how we'll charge the necklace. I also want the on/off switch to be easy to reach. I wound the silicone wire leads around beneath the ItsyBitsy and hot glued it into place.
From the side, you can see that all the electronics are barely 1/4" thick - not even as thick as the resin cabochon. This should make a really nice low-profile necklace.
There are lots of wire wrapping tutorials online that go into a lot of detail. I'm just a beginner but I'm still able to get some really beautiful designs. Here are the basics. I've gone into more detail over on my blog.
I cut a piece of leather to the same size of my pendant and hot glued it to the back, over the electronics.
Then I cut 6 pieces of wire to around 14" long. I'm using a combination of square and round wire for this particular pendant. The wire can be anywhere from 16g to 22g, depending on the look you're going for.
Line up your 6 pieces of wire - I found taping them to the table really helped keep them neat. Cut another small piece of wire and bend it around the 6 wires right in the center to hold them all together. This will become the bezel, the main loop that goes around your pendant.
Find something with a slightly smaller diameter than your pendant to use as a mandrel. I found a pill bottle that was the perfect size. Bend your bezel around the mandrel and secure it on the other side with another wire wrap around all 12 pieces of wire.
Place your pendant inside the bezel and tighten it down. Spread out the wires on the front and back edges of the bezel to hold the pendant securely in place. Make sure your on/off switch and your USB port are accessible. This method gives you a lot of freedom in designing your setting so you can cover any battery corners while keeping your components in easy reach.
Make a bail at the top for the necklace chain to go through using 4-5 of the wire ends. Wrap some of the rest around to secure the bail.
Finish up by artfully bending the rest of the wire tails into spirals or rosettes or whatever suits your fancy. I made a Pinterest board of wire wrapped jewelry examples for inspiration. Pinterest knows my secret heart so well.
Finish off with a necklace chain and enjoy your beautiful glowing amulet pendant.