The facing sides of German style scissors are flat. The facing sides of Japanese style scissors have a slight hollow ground area behind the cutting edge. leaving a very thin smooth flat spot called the “hone line”. The blades of the scissor glide along the “hone line” and the edge cuts the hair. Properly sharpened the cutting edges do not come in contact and dull each other. The hollow area prevents hair from slipping between the blades and pushing them apart.
The sharpened edge of Japanese style scissors is made much sharper (more acute angle) than the German style scissor. The Japanese style scissor cuts like a razor and needs to be razor sharp. The German style scissor cuts more in a chopping action and the sharpened angle is less acute.. Each has its advantages, many barbers prefer the German style, for scissor over comb cutting. However, that would not be good for slide cutting or precision cutting. That requires the razor edge of a Japanese style scissor preferred by many hairstylists.
Beveled edge: at the cutting edge of the blade there is a distinct bevel (angled line). All German style scissors have a beveled edge as do some Japanese style scissors.
Convex edge: at the cutting edge there is no distinct bevel. The outside of the scissor blade slopes smoothly into the cutting edge. This gives the edge more strength. Another reason is cosmetic. When you create a very sharp angle it makes a very wide bevel, but if you smooth it out it looks much better.
Corrugated Edge: is normally associated with German Style scissors. The object of the courrugation is to keep the hair from sliding out of the blade while the smooth blade cuts the hair. It can also be put on to Japanese style scissors for the same effect. Some stylists who do a lot of tip cutting like corrugation put only at the tip of the blade.That allows the scissor to also do slide cutting
One more thing common to both Japanese and German scissors, for scissors to cut, the blades must come together at only one point. To make this happen both blades are bent very slightly towards each other. This is called the “set” or “balance” of the blade.
Both Japanese style scissors and German style scissors are manufactured in many countries around the world. Many countries have factories that make both styles.