Polymaker Easy to Sand & Paint PLA Filament CosPLA (Version B - Sand-Ability with Extra Durability), PolyLite 3D Printer Filament 5kg 3D Printing PLA Filament Easy Sanding for Cosplay

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.