What is the difference between UD/3K/3K twill/12K/12K twill?
The main difference is "appearance" and "weight". UD is the lightest, 3K/3K twill/12K/12K twill is 0.05% heavier than UD. Because they weave carbon fiber yarn in different ways, it will affect the fluidity of resin and make the whole weight heavier. But their stiffness is the same, and all resins in carbon fiber are the same, no matter what kind of surface.