One button--the middle on the middle row--is Bakelite. Most of the others are celluloid, except the two left on the bottom row. The inner of the two is MOP, and I'm unsure of the outer one.
The buttons came from a button box I was given by an elderly neighbor. The box had belonged to her grandmother and, as my neighbor is now in her eighties, I've calculated the box itself must date back to the turn of the last century as, most likely, do many of the buttons.
I've used vintage-looking scrapbook paper as a backing for the shadow box.
My home is smoke-free; my studio is also pet-free.