We are currently using the Avery 4021 Avery 4021 Dot matrix printer white addressing labels, 3 x 15/16, 4 across, 20000/box, but are experiencing a lot of paper jams on our IBM 6400 printer. The paper that the labels are mounted on appears to be extremely light and the feeding tractors rip it very easily, causing paper jams, wasted labels, and multiple reprints to get what we need. The tractor margin also seems a bit wider than the last box that we had. We have been using these same labels for several years and this box is really giving us problems.I have been trying to use less tension, but then the print quality seems to be less, too.We have had the printer checked by a qualified technician, but no easy solution to this problem has been found.