Lines on printed pages follow a pattern, and their direction and color tell you where to look. On inkjets, thin white gaps running across the page usually mean clogged nozzles, while ink marks running in the direction of paper travel point to something dirty in the paper path. On laser printers, lines down the page usually trace back to the drum, toner cartridge or a dirty corona wire. This guide shows how to read the pattern and fix each cause, starting with the simplest check.
What you might be seeing
- Thin white lines run across text and images
- Dark streaks run down the page in the direction it feeds
- Lines appear on copies but not on prints from the computer
- Gaps or stripes appear in solid areas of one color
Common causes
- Clogged inkjet nozzles
- Blocked nozzles leave unprinted strips each time the printhead passes.
- Ink on rollers or the platen
- Overspray or an earlier jam can leave ink inside that transfers to new sheets.
- Drum or corona wire marks
- A scratch on a laser drum or dirt on the charge wire prints as a line down every page.
- Dirty scanner glass
- Dust or a smudge on the scanner strip creates lines on copies only.
How to fix it, step by step
Work through these in order and test a print after each one. Most people are done within the first few steps.
Unplug the printer before cleaning inside it. Never touch a laser drum's surface or inkjet nozzles, and do not use solvents on either.
Find out whether only copies are affected
On an all-in-one, print a document from your computer and then copy a clean page. If only the copy shows lines, the print engine is fine and the scanner glass needs cleaning. Lift the lid and wipe the main glass and the narrow strip the document feeder reads through, using a lint-free cloth lightly sprayed with glass cleaner or water. Never spray liquid onto the glass itself.
Print a diagnostic page to read the pattern
Print a nozzle check on an inkjet, or a print quality or demo page on a laser, from the control panel or the manufacturer's app. Broken or missing lines in an inkjet nozzle check point to clogs. Lines running down the page in the same position on every sheet point to something the paper passes over, such as a roller, drum or fuser.
Clean the inkjet printhead
If the nozzle check shows gaps, run the printhead cleaning function from the control panel, the manufacturer's app, or the maintenance tab some drivers include in Printing Preferences. Print another nozzle check afterward. Start with a standard cleaning and use a deeper cleaning only if gaps remain after two attempts, since deep cleaning uses much more ink.
Clean ink from the inkjet paper path
If marks run in the direction of feed or appear on the backs of pages, ink has built up on rollers or the platen, the ribbed surface beneath the printhead. Many inkjets offer a paper path or platen cleaning routine that feeds a sheet through. For stubborn marks, unplug the printer and dab the platen ribs with a cotton swab barely dampened with water, keeping clear of the printhead and the ink absorber pads.
Redistribute toner and inspect the drum
On a laser printer, light streaks down the page often mean toner has settled unevenly. Turn the printer off, unplug it, remove the toner cartridge and rock it gently side to side. If your drum is a separate unit, look at its surface under good light for scratches or stuck debris without touching it. Reinstall everything and print a page with large solid areas.
Clean the corona wire on separate drum units
Many laser printers with a separate drum unit have a corona wire cleaner, usually a small colored tab on top of the drum. Slide it gently from one end to the other several times, then return it to its home position, since a tab left midway causes a line of its own. A dirty corona wire typically produces dark or light lines running down the page.
Swap the part that carries the line
If lines continue after cleaning, try a known-good cartridge or drum if you have one. On a laser, a line that follows the toner cartridge means the cartridge is at fault, while one that stays with the drum means the drum is worn or scratched. On inkjets that use cartridges with an integrated printhead, a new cartridge also gives you a new printhead.
How to keep it from happening again
- Print a color page weekly to keep inkjet nozzles clear
- Keep the scanner glass and feeder strip clean
- Turn the printer off with its own button so the printhead caps
- Avoid printing on dusty or damaged paper
Common questions
Why do lines appear in only one color?
When one color shows streaks or gaps, that color's nozzles are partly blocked or its cartridge is nearly empty. A nozzle check confirms which one. Clean the printhead, and replace the cartridge if it is low. On color laser printers, a streak in a single color points to that color's toner cartridge or drum.
Do cleaning cycles waste ink?
Each cycle pushes ink through the nozzles to clear them, so it uses more than a normal page, and deep cleanings use more still. Run cleanings only when a nozzle check shows gaps, and stop after a few rounds. Light, regular use costs less than repeated cleanings because it keeps nozzles from drying out.
What is the difference between streaks and banding?
Lines caused by something the paper passes over run lengthwise down the page, while lines from an inkjet printhead pass run across it. Banding describes a repeating pattern of lighter and darker stripes across an image, most visible in photos and solid fills. A test page with large solid areas helps you tell them apart.
This guide is general information written for common home and office printers. Menus and button names vary between models, so check your printer’s manual where a step differs. Printer Problems Solved is independent and not affiliated with any printer manufacturer. See our disclaimer.