Evidently should have added that the laser printer involved was a Hp Laser printer. Evidently they will work on Epson's but read those directions first. That I don't know about, but a friend of mine just had hers ruined by a teacher making labels in it. The teacher did not read the directions that came with it.
Labels have to be hand fed into a laser printer even if they are laser labels.
Her printers drum is now covered with labels and no longer work because the labels were put in the feeder tray instead of hand fed per directions.