Two things: the quality of the metal and the workmanship. Inexpensive shears are made of inexpensive steel that will not hone to as fine an edge as a better grade, more expensive, metal. This effects the sharpness of the scissor blades and how well they hold an edge, as well as the smoothness of the blade action. You want sharpness in order not to bend the hair while cutting, and to provide good definition in your cuts. The action of the two blades determines the amount of effort it takes to open and close the blades as well as the smoothness of cutting strokes. All RnK scissors are made of High grade (420C/440C) Japanese Stainless Steel. This ensures an effortless, smooth and precise cut. The workmanship is another factor influencing the scissoring action. Cheap shears are assembly line produced with much of the work done by machine. The best shears are handcrafted by trained artisans who take responsibility for each tool from start to finish. As we manufacture handmade scissors only, you get the finest quality when you purchase an RnK shear.