User blog comment:Voikus/Black swords/@comment-108.83.222.210-20200610040457

a curious idea. It actually brings to mind something I head mentioned regarding martial arts if you will pardon the deviation from the subject. I understand that in some martial arts originally there was only one belt color and since the belts are not washed, they will collect dirt, grime, and blood over time. Therefore eventually these things will turn the belt black, hence black belt. I wonder if the swords in this manga are the same in that regard in that they eventually change color permanently if this happens enough times.