Marking blue — Marking blue, layout stain or Prussian blue is usually a dye used in metalworking to aid in marking out rough sections for more machining. It is usually identified as Dykem (after a preferred model). It's accustomed to stain or paint a steel item with an exceedingly thin… http://bollardsinstallation90963.blogolenta.com/9818574/mechanic-shop-floor-marking-secrets