Yes, you can get quite a bit of that if you sand the inside of the case.
1 So polycarbonate is recycled (CDs) and can be recycled again (?)
"Products made from polycarbonate can contain the precursor monomer
bisphenol A (BPA" from wikipedia, is worrying.
2 This leads me to believe adding colour will weaken, (if only ever so slightly) the case?
3 Colour sounds more complex, in turn possibly leading to issues with recycling or production.
Especially "metal" sounds like something that sheilds wireless signals.
4 And basic polycarbonate is even cheaper to produce? Could be win-win.
Clear is cool, as I can take off a part, and plastic-paint the inside if I want it to have a colour.
Many colours and possibilities there.
This, as with a solid colour, wont wear down.
5 So how good is this polycarbonate over time? Same properties as a CD?
Cam it be