Black Ceramic Pocket Knife Blade or White Blade? OK, there some increased hardness in a black ceramic knife blade but in reality the white blade is already so hard that this increase makes very little difference in terms of the ability to retain an edge. The only real reason, in my opinion, to purchase a black ceramic folding pocket knife is one of appearance. It just feels strange using a knife with a white blade that you can almost see through. The black blade on a ceramic pocket knife gives a much more traditional appearance & darn it, just plain looks better! The black blades are however, more expensive to produce, as they have to go through a secondary Hot Isostatic Process where pressure and extremely high temperatures physically change the blade from white to black and increase density & hardness. Keep in mind that increased hardness does also increase brittleness so a white ceramic bladed knife might actually be tougher in some applications as it would be more resistant to chipping.