HP Designjet T1300 ePrinter - Manual (Page 166)

3. Try to move the printhead carriage out of the way.
4. Lift the blue lever as far up as it will go.
5. Carefully remove any of the jammed paper that you can lift up and out from the top of the printer.
CAUTION: Do not move the paper sideways, as it could damage the printer.
158 Chapter 16 Troubleshooting paper issues ENWW