HP Laserjet 1200 - Manual (Page 18)

16 Chapter 1 Getting to know the printer EN
Printer input trays
Main input tray
The enclosed main input tray, located in front of the printer, holds
up to 250 sheets of 20 lb paper, multiple envelopes, or other
media.
Priority input tray
You should use the priority input tray when feeding up to
10 sheets of 20 lb paper or when printing single envelopes,
postcards, labels, or transparencies. You can also use the priority
input tray to print the first page on different media than the rest of
the document.
Note The printer automatically prints from the priority input tray before
printing from the main input tray.
See Media for more information about media types.