HP Color LaserJet Enterprise flow M880 Multifunction Printer series - Manual (Page 28)

4. Make sure that the paper fits under the fill line on
the paper guides.
5. Adjust the side guides so that they lightly touch
the paper stack, but do not bend it.
Table 2-1 Tray 1 paper orientation
Paper type Image orientation Duplex mode How to load paper
Preprinted, letterhead, or
labels
Portrait 1-sided printing Face-down
Top edge toward the back of the product
18 Chapter 2 Paper trays ENWW