Inkjet print defects are unusually informative. The shape of the problem — horizontal bands, vertical streaks, a missing colour, a general fade — points to a specific cause, and treating the wrong one wastes ink on cleaning cycles that were never going to help.
This guide maps each pattern to its likely cause and covers how to clear a blockage without wasting a cartridge.
Cleaning routines and alignment procedures are model-specific, so the Canon manuals PDF for your printer are the right reference before running anything.
Start with a nozzle check
Every inkjet printer can print a nozzle check or print quality diagnostic page from its own control panel. It prints a test pattern for each colour, usually as a series of fine lines or blocks.
- Complete, unbroken patterns for every colour mean the print head is clear and the fault lies elsewhere — in the driver settings, the paper or the file.
- Gaps or missing segments in one colour indicate blocked nozzles in that channel.
- An entire colour missing indicates either a severe blockage or an empty or unrecognised cartridge.
Print this page first. It converts a vague complaint into a specific diagnosis and takes one sheet.
Horizontal bands or gaps across the page
This is the classic blocked-nozzle pattern. Ink has dried in one or more nozzles, usually because the printer has been unused for a period.
The correct approach is graduated, because head cleaning consumes a surprising amount of ink:
- Run one head cleaning cycle, then a nozzle check. Do not run several cleanings back to back.
- If it improved but is not clear, run one more and check again.
- If two cycles produce no change, stop. A third and fourth will not help and will consume ink.
- Leave the printer switched on and idle for a few hours. Many printers run a light maintenance routine on their own, and standing time allows solvent to soften dried ink.
- Then try one more cleaning cycle.
If the blockage persists after that, the head may need a deeper clean. On printers with removable print heads this is a manual procedure; on printers where the head is built into the cartridge, replacing the cartridge replaces the head and resolves it directly.
Vertical streaks or lines
A different cause entirely. Vertical marks running in the direction of paper travel usually indicate contamination on the paper path or head carriage rather than a nozzle problem.
- Check for dried ink on the rollers and the area beneath the head.
- Run the printer’s paper path cleaning routine if it has one.
- Check whether a previous jam left residue or a paper fragment in the path.
- Marks on the reverse of the page indicate ink on a roller rather than a print head issue.
Misaligned or fuzzy output
If text has a slight double edge or vertical lines look ragged, the print head alignment is out. Every inkjet has an alignment routine in its maintenance menu, which prints patterns and either reads them automatically or asks you to choose the best.
Run alignment after any cartridge change, after moving the printer, and whenever output looks soft without any banding.
General fading or weak colour
- Check ink levels, remembering that reported levels are estimates rather than measurements.
- Check the print quality setting in the driver. Draft mode uses far less ink and is frequently left on by accident.
- Check the paper type setting matches the paper. Printing on photo paper with a plain paper setting lays down the wrong ink volume and produces flat, weak results.
- Check the correct paper side is facing the print head. Photo and coated papers are single-sided.
Cartridge problems
- Confirm all protective tape and packaging was removed from a new cartridge. This is the most common cause of a colour missing immediately after a change.
- Check the cartridge is seated and latched. A cartridge that clicks in but sits proud will not make contact.
- Clean the copper contacts on the cartridge and in the carriage with a dry lint-free cloth.
- Cartridges have a shelf life and dry out. One that sat in a drawer for two years may never work properly.
- Third-party and refilled cartridges vary considerably in quality, and refilled cartridges with clogged heads are a frequent source of persistent banding.
Why inkjets clog, and how to prevent it
Inkjet ink is water-based and dries in air. The print head has extremely fine nozzles, and when the printer sits unused, ink at the nozzle plate dries and blocks them. Printers park the head in a capping station to slow this down, which is why you should always switch off using the printer’s own power button rather than a switched socket — cutting power abruptly can leave the head uncapped.
- Print something at least once a fortnight, even a single colour page.
- Switch off with the printer’s own button so it parks the head.
- Keep the printer out of direct sunlight and away from heat, which accelerates drying.
- Do not leave the printer with an empty cartridge installed for long periods.
Ink systems differ enough between ranges that it is worth being able to download user manuals in PDF for the exact printer rather than following a general video.
When repeated cleaning is the wrong answer
Head cleaning cycles consume ink from every cartridge, not only the blocked one. Running many cycles in succession can empty a set of cartridges while achieving nothing. If two or three cycles with rest periods between them produce no improvement, the problem needs a different approach rather than more of the same.
Frequently asked questions
Are ink levels accurate?
They are estimates based on how much ink the printer believes it has used. They can read empty with ink remaining, or read low for a long time.
Is it worth repairing an inkjet with a permanently blocked head?
Rarely, on a consumer model. A replacement head, where one is even available, often approaches the cost of a new printer.
Do I have to use original cartridges?
No, though quality varies. Where the print head is part of the cartridge, cartridge quality determines print quality directly.
