If you discover your HP printer is printing from the wrong paper tray there are two places (on the printer) you should begin your search.

First, look on your PC (the one you are printing from). The printer settings, accessible from your PC, may be set to print from a different paper tray than you think. You should open your printer control application and click on PRINTER PROPERTIES, then find the TRAY SELECTION drop down and select the tray you want.

Second, you should look on the printer. You should make sure the paper sizes in the control panel match the paper that is actually in the paper tray.

Read: Problem Number 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1