HP Deskjet 3820 Color Inkjet Printer - Manual (Page 14)

paper trays
The printer has a fold-up paper tray and an output guide. The output guide contains a
slot for single envelope or index card printing.
1. single envelope slot 2. fold-up tray 3. output guide
In tray
Open the space-saving fold-up tray to load paper or other media to be printed.
You can print different sizes of media by adjusting the paper width guide and the
paper length guide.
Unfold the extension on the In tray when printing.
1. paper length guide 2. In tray extension 3. paper width guide