I actually use a thinner plastic called PETG (same as in coke bottles), in both the ear rings and the pane at the top of the jewelery boxes. It’s thinner, flexible and cheaper than acrylic, while still being pretty durable. The only downside is as a thermoplastic there are limits on what you can do to it with a laser before it starts to warp and distort. You have to use a light touch; the ear rings take about 6-9 passes at full speed, 13% power to etch away the stained glass paint. But the end result is something so light that you can’t even feel that you’re wearing them.
The blue wood is a wood dye I bought on Amazon – the wood really soaks it up well, but it stays on the top layer so much that a light engraving etches it all away, which creates that stark contrast. That was a particularly happy accident.