This carbon on the side is a 4X4 Twill weave. It's commonly used as a last layer of Formula One frames as a cosmetic layer. The weave shows off the 3D effect better than a 2X2 weave. Bend your knee with Jeans on and look closely, you'll see a Twill weave which is pretty good at bending to contours better than some other weaves. Levi Strauss was a canvas company that started making jeans. Who would've thought.