Composites are made from resin reinforced with fibers. Glass fiber reinforced thermoplastic and thermo-stamped composite are two types common in high-quality cases. Composites have greater strength and impact absorption than most materials. It won’t become brittle or warp in extreme low and high temperatures. It doesn’t need to be painted or anodized. And, some formulas can shield EMI/RFI. In short, it’s one of the most dependable materials used in containers and cases.