decided to etch my knives other day, had nice results.
hard part was finding a container large enough to fit nearly 11" gyuto, used a tall plastic cereal saver box.
mostly filled with warm water, then 250mL of ferric chloride. so a very diluted solution.
3 times at 1 minute intervals, scrubbed with 0000 steel wool in between each dunk and cleaned with soap after final soak.
left to right:
watanabe 270, shigefusa 240, tanaka 210, tanaka 105
my reason for doing this was not to make it look cool, but in hopes to make it less reactive and offer some sort of protection. the looking badass is just a bonus. after using them they stink less and aren't leaking all sorts of marks on the blade as crazy as before. perhaps forcing a mustard patina OVER this acid etch would serve to be even more robust.