Kurouchi is the basic, rustic finish on Japanese knives. The blade is essentially left unfinished except for it's very edge. Kurouchi blades are blue blackish in color, and often times the bevel displays hammer and grinder marks. It is a rough, rustic beauty, that goes well with knives that are meant to be "work horses" rather than "show pieces". The hammered kurouchi finish will display both hammer and grinder marks above and below the shinogi line.