出典:Wikipedia
出典:『Wikipedia』 (2010/07/17 03:30 UTC 版)
Marking blue, layout stain or Prussian blue is a dye used in metalworking to aid in marking out rough parts for further machining. It is sometimes called Dykem (after a popular brand). It is used to stain or paint a metal object with a very thin layer of dye that can be scratched off using a scriber or other sharp instrument to reveal a bright, yet very narrow line in the metal underneath. The advantages are that any existing scratches are covered with the dye and the new lines have a contrasting background.