if the # on the spool starts with 713 it is 12 weight thread--if it starts with 733 it is 30 weight thread. I don't know what size spool you have. the spool that has 330 yards on it is 12 weight it's listed on the paper disc on either side of the spool. the spool that has 500 yards is a 30 weight thread. the label is brown and white. the 12 weight thread label is brown , white and orange. hope this helps. Anne