FR4
FR4 is a class of glass fiber epoxy laminate that is flame retardant.
Acetal (POM-C) is the easiest to machine engineering Plastic. Ideal for parts with high stiffness, low friction and very low water absorption.
High performance engineering thermoPlastic polymer, with excellent durability, strength, stiffness and heat resistance (UL94-V0).
PMMA is a translucent rigid Plastic, often used as a substitute for glass and when high transparency is needed, a high polishing process can be done to achieve this.