Blinking Alien Spaceship Book Using Neopixels & an ATtiny85

Solder the neopixels before removing the adhesive from the copper tape.

In the process of prototyping, to see if I could get individually addressable neopixels (surface mounted RGB LEDs) to work in a paper circuit, I've learned a couple of tricks.
The most important one is to solder the LEDs to the copper tape before creating the rest of the circuit. Compared to my first botched attempt, in which I tried to solder neopixels to copper that was already adhered to paper, soldering the LEDs to the copper first was far less fiddly.

Although I had to use a multimeter to isolate a wonky joint (the result to too many cross-overs) I was eventually able to get three LEDs to work the way I'd intended.  Each light changes colors!

In this project, I've added a LilyPad button board in addition to a LilyPad slide switch.

Something else that I've done differently is add two layers of watercolor paper to the binder's board, with notches cut out for the LEDs, button, and switch.  Neopixels are thicker than other SMD LEDs, so the extra paper helps smooth out the surface of the book covers.  I added one layer of watercolor paper to the inside covers as well, hoping to increase the surface tension on the battery. 

Rough sketch

I painted the design and sealed it with acrylic gel medium.