I was lurking and reading through the Prometheus Discord and found out that glass is a viable alternative to the industry-standard aluminium: 

This has a multitude of benefits:

• Glass is much harder to scratch than aluminium
  • important as one of the project goals is consumer-friendliness
• Glass is cheaper and can be found in many different finishes (clear, frosted, opaque color, image-backed)
• Glass is non-conductive, increasing the chance that my electrostatic cleaning approach idea will work on the first few layers.