Line. In button manufacture, one-fortieth of an inch; the size of buttons being denoted by the number of lines across the diameter. Thus a 22-line button equals twenty-two-fortieths of an inch from side to side; an 18-line, eighteen-fortieths of an inch, etc. The term is also used in indicating the width of braids, etc., having reference to the number of ribs or plaits in the width.