A technician is troubleshooting poor printing quality on an inkjet printer.

White lines running through text and graphics in printouts from an inkjet printer are commonly caused by clogged printheads. When the printhead nozzles are clogged, they cannot deliver ink properly to the paper, resulting in white lines where ink should have been deposited. Worn-out rollers, faulty ink cartridges, and poor-quality paper can cause other printing issues but are less likely to cause white lines in the printed output.