IBM 19 - Manual (Page 264)

4. Lift the stacker arm and load 30 or fewer envelopes
printing-side up, so that the flap side will be on the left when
the envelope is pulled into the printer (fig. 8.8).
5. Lower the stacker arm.
Fig. 8.8 Load the envelopes
Chapter 8
8 - 8 P r i n t e r O p t i o n s
EDNord - Istedgade 37A - 9000 Aalborg - telefon 96333500