HYLOMAR BLUE: GASKET & SEALANT 350M CARTRIDGE JN75

* Dries immediately * Gives clear view * Blue surface for precise and accurate marking out * A New Zealand Product Marking blue or layout stain (sometimes called Dykem after trademark erosion of a popular brand, or Prussian blue after the blue pigment) is a dye used in metalworking to aid in marking out rough parts for further machining. 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.