From our friends at ProtoPasta:
Our most popular exotic material, Proto-pasta Carbon Fiber Composite HTPLA is a combination of milled carbon fibers and high-performance PLA. Resulting 3D prints made with our Carbon Fiber HTPLA are demonstrably more rigid, providing excellent structural strength and layer adhesion with very low warpage. The embedded carbon provides a beautiful light matte gray finish with a slight sheen, resulting in 3D prints with exceptional accuracy, finish, and performance!
What is HTPLA and how does it work?