Epson PRO Reference Manual page 22

Load the paper or transparencies firmly against the right side
of the paper tray. Slide the stack into the tray until you feel
some resistance. Then slide the left edge guide against the
left edge of the paper stack.
5. Slide the rear edge guide against the rear edge of the paper.
6. Change the Media Type and other printer driver settings to
match the paper or transparencies you loaded as described
in your Setup and Software Guide.
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Paper Handling