Polymaker Fiberon PPS-CF10 Filament Black 3kg, Extreme Heat Resistance - Fiberon Carbon Fiber Reinforced PPS 3D Printing Filament Ideal for Molding

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.