Polymaker Fiberon PET-CF17 3D Printing Filament Black 1kg, Excellent Stable Stiffness - Fiberon Carbon Fiber Reinforced PET 3D Printer Filament, Ideal for Jigs and Fixtures

The most engineering-minded consumer brand in this space. Polylite is their everyday PLA, PolyMax adds impact resistance, and PolyWood nails the timber look. They publish data sheets and actually explain what's in their formulations.