Epson TM-C3400 Reference Manual page 84

4. Adjusting roll paper guide/paper ejection guide
This procedure is not required when paper width is not changed.
1
Press down the release lever, and pull it to the front to open the roll
paper cover.
2
Unlock the roll paper guide.
3
Push the paper guide on the left in the direction of the arrow, and load
the roll paper with the printing side up.
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