Traditionally every saya might be made for my part for each sword and the in shape would be be ideal, at least on the throat so it would be friction geared up. and you may notice almost every protect has as a minimum one regularly two symmetrical holes in it wherein the flat of the blade is far sufficient out shape the center that they arent blanketed through the saya whilst sheathed. this is for the small knife or hairpin that goes within the saya, but additionally so that you can run a twine or sageo through it which I have heard called a "peace tie". I don't understand how commonplace this was throughout records and wether this became best performed whilst storing the sword (you can find tanto swords at this site) or worn this manner, but it works as a pleasing safety.
