This knife is a practicable sheath knife. The shape of our blade is dual convex. The technologically advanced process and materials used in the production of the blade, prohibits others from creating anythig similar and we have cofidence in our blades suface. When pushed with force,this knife will cut though a phone book as if it were butter. Please confirm the improved sharpness of our evolved dual convex blade. ZDP189 is a powder stainless steel steel developed through the use of nanotechnology specifically for cutting through implemets. The sharpness of this ZDP189 blade was not really affected after cutting through hard manila rope 780 times. However, this knife is not well suited to chopping. This knife is full tang.