Jerry: There were folks etching blades for longer than that. The reference to functional balance comes from being able to see the entire spectrum, soft to transition zones to hard. WE have been able to learn much more than a simple soft hard comparison as available from the scale or sanding the surface. From reading the etch, we have a good idea of the structure inside the blade as it is mirrored in the transition zones. I have found what I consider defective blades thanks to the etch that would not have been obvious otherwise. I have also learned more about the steel we use. There is nothing new about knives other than the nature of the steel we have available to us now that was not available to bladesmiths in the past. By etching historic blades we can gain some insight into their methods. The etch is a source of immediate feedback to the bladesmith who seeks to get the most out of the steel he uses. The more you learn, the more you can read from the etch. Comparison performance testing must be used in conjuction with the etch to validiate what you see. The evidence available to the blade smith at the time of hardening (scale) is long gone when the client views the knife. Etching blades has taught me that reading the scale is not always as accurate as I once thought. Sanding the blade is also a little short of the whole story. There is much more to the nature of the steel than a simple hard soft comparison. I want to know more about my blades and will seek that information any way I can get it. I have been etching blades for over 15 years. The etch still provides one of my great pleasures, just like Christmas when I get to read the blade.