HP Color LaserJet 5550 Printer series - Manual (Page 103)

2. Slide the paper width and length guides all the way out.
3. Load media face-up, making sure that the stack height of the paper does not exceed the
maximum stack height mark in the tray.
4. Slide the paper width and length guides in, making sure that they gently touch the paper.
5. Verify that the tray switch is set to CUSTOM.
ENWW Configuring input trays 89