Hi PAWPAW41, Load envelopes into the paper tray face down, with the flap edge all the way to the left. The ET-3760's specification is for loading 10 envelopes at a time, but if this does not work, try flattening the envelopes or putting less than 10 in the tray. There are helpful FAQs and user guides with envelope-printing tips on the Epson support site. Regards, Mark - The Epson Team.