What you are seeing
This fix gets the code onto the correct stock. You will identify the stock that was used, compare it with the stock the job requires, and reprint a single proof on the right material. Update the job ticket so the next reprint uses the same correct stock.
Likely causes
1.
Wrong tray or stock loaded — Quick test: check the stock in the tray against the job ticket.
2.
Stock substituted without notice — Quick test: compare the used stock with the specified stock.
3.
Job ticket never named the stock — Quick test: check whether the job ticket names the stock.
4.
Stock unsuited to the printer — Quick test: check the stock against the printer's recommended media.
5.
Stock unsuited to the environment — Quick test: check the stock against the conditions where the code will live.
Step-by-step fix
Step 1: Identify the stock that was actually used. Compare it with the stock the job specifies.
Step 2: Check the printer tray selection and confirm the correct tray is loaded.
Step 3: Choose the correct stock for the printer and for the conditions where the code will live.
Step 4: Print one proof on the correct stock and scan it on two phones.
Step 5: Update the job ticket to name the stock, the tray, and the print settings.
Step 6: Reprint the run on the correct stock.
Step 7: Spot-check the first copies against the proof and confirm the stock matches the ticket.
Putting this into practice
In practice, keep a sample of the approved stock with the job file. When a reprint arrives on the wrong paper, comparing it with that sample settles the question in seconds. 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
- Leaving the stock off the job ticket and discovering the run was printed on whatever was loaded.
- 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 on the wrong paper will be used.
- Changing the artwork and the placement at the same time, so you cannot tell which change fixed a code that prints on the wrong paper.- Skipping the proof test because the change looked small, when small changes cause most repeat failures.
Quick checklist
- The stock matches the job ticket
- The stock suits the printer and the environment
- The proof on the correct stock 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)
