Epson Stylus COLOR 3000 User Manual page 144

When you load envelopes into the manual feed slot,
position the right edge guide so that its right edge is even
with the arrow mark on top of the manual feed guide. Load
envelopes flap side down with the flap edge first. See
"Loading paper manually" on page 5-6.
Do not print on the back side of envelopes.
Do not use envelopes that are curled, folded, or partially
sealed. Also, avoid using envelopes that are too thin; they
may curl during printing.
Select Plain Paper as the Media Type setting in the printer
driver. For more details on making printer driver settings,
see online help for Windows, or Chapter 4 for Macintosh.
Return unused envelopes to their original packages.
Unfavorable storage conditions such as high temperature
or humidity can damage them.
If your envelopes jam or don't feed properly, see
Chapter 8, "Troubleshooting."
5-28
Paper Handling