Epson 1500 - Manual (Page 130)

The Face-up Output Tray
The printer normally delivers paper face down on top of the
printer. The optional face-up paper tray is recommended for
print jobs of twenty pages or less and when:
you feed single-sheet items such as envelopes,
transparencies, heavy paper, or labels through your printer.
you prefer your printed sheets feed from the printer with
the text facing you.
Installing the face-up output tray
1. Hold the output tray tilted at a slight angle away from you.
Then insert it into the back of the printer by placing the pins
on the bottom side comers of the tray into the holes on each
side of the paper ejection slot one at a time as shown below.
5-16 Options