What you are seeing
This fix removes the banding from the print by finding the printer fault that causes it. You will clean and test the printer, adjust the print settings, and reprint a single proof until the bands are gone. Do not approve a run while banding is visible, because a band that looks mild can still break the code.
Likely causes
1.
Clogged or misaligned print head — Quick test: print the printer's nozzle check or alignment page.
2.
Draft or high-speed print mode — Quick test: reprint the same file at normal or high quality.
3.
Low ink or toner — Quick test: check the ink or toner levels and print a test page.
4.
Paper feed problem — Quick test: check whether the bands appear in the same place on every copy.
5.
Wrong media setting — Quick test: confirm the media setting matches the stock.
Step-by-step fix
Step 1: Print the printer's nozzle check and alignment page. Fix any fault it shows.
Step 2: Run the printer's head-cleaning routine, then reprint the test page and confirm the bands are gone.
Step 3: Switch the print mode to normal or high quality and reprint one proof of the code.
Step 4: Check the ink or toner level, and replace a low cartridge before reprinting.
Step 5: Confirm the media setting matches the stock, and adjust it if the stock changed.
Step 6: Check the paper feed: use fresh, flat stock and confirm the bands do not repeat in the same place.
Step 7: Reprint one proof and confirm it is band-free and scans on two phones before approving the run.
Putting this into practice
In practice, keep a dated note of the last head cleaning and cartridge change with the printer. When banding appears, that note tells you whether maintenance is overdue or the fault is new. Record the before-and-after behaviour with the job file, so the fix is provable rather than anecdotal. When the same failure appears again, that record tells you whether the old fix held or a new cause appeared.
Common mistakes to avoid
- Reprinting the full run on a banding printer in the hope that the next copies will come out clean.
- Reprinting the full run before a single proof passes, which turns one failure into many.
- Testing on one phone in ideal conditions instead of two phones in the real conditions where a code that prints with banding lines will be used.
- Changing the artwork and the placement at the same time, so you cannot tell which change fixed a code that prints with banding lines.- Skipping the proof test because the change looked small, when small changes cause most repeat failures.
Quick checklist
- The nozzle check and test page are clean
- The proof shows no banding lines
- The proof scans on two phones
- The corrected proof passes on two phones in the real conditions
- The fix is recorded in the job file so the next reprint starts from a proven setup
- Every printed copy is checked against the approved proof
- The proof is retested after any later change to the link, design, or placement
Related tools and guides
- [QR minimum size checker](/qr-minimum-size-checker)
- [QR contrast checker](/qr-contrast-checker)
- [QR print proof checklist](/qr-print-proof-checklist)
- [QR DPI calculator](/qr-dpi-calculator)
- [QR quiet zone calculator](/qr-quiet-zone-calculator)
- [printed QR tester](/printed-qr-tester)
- [QR size calculator](/qr-size-calculator)
