Epson FX-2190 Reference Manual page 64

To load single envelopes, follow the instructions in "Loading
paper in the paper guide" on page 51. To load multiple envelopes,
see "Loading paper in the high-capacity cut-sheet feeder" on page
180. Load envelopes with the printable side down and push them
completely into the feed slot.
Note:
❏ Be sure to place the envelope printable side down and insert the top
edge of the envelope into the printer first.
❏ The print head must not print past the left or right edge of the
envelope or other thick paper. Make sure your application program
prints entirely within the printable area of your envelope. See
"Printable area" on page 219 for more information on the printable
area of envelopes.
❏ If you are using No. 6 envelopes, make sure the left edge guide is
aligned with the arrow on the paper guide.
58 Paper Handling