Epson 1270 Daily Use page 18

Load envelopes flap edge first with the flap side down, as
shown in the illustration.
Available envelopes sizes are:
No.10, DL, C6, 132 mm 220 mm
Do not use envelopes that are curled or folded. Make sure to
flatten the envelope flaps before loading. 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.
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