The vein became mainstream in the tackle world during Covid when one of the members of a bait making Facebook page (his mind slips me) started applying it over different colors and getting deep tears to reveal the under color. Had everyone buying it including me, lol. Before this vein was just used as a color itself, dipped in clear and baked. You’d get minimal tearing and then just whatever color the vein paint you were using. That’s how the powder coat world still uses it.