Sorters read bars and gaps at conveyor speed. Everything on this page exists to protect that one strip of ink.
Five symptoms, five settings
| What came out | What usually caused it | The fix |
|---|---|---|
| Label shrunk, huge margins | Fit-to-page scaling in the print dialog | Set scale to 100 percent or actual size, then print again |
| Edges or barcode chopped off | Paper size mismatch — a 4 x 6 file sent to letter settings, or the reverse | Match the media size in the driver to the stock in the tray |
| Faint bands or streaks through the bars | Ink or toner running dry, or draft mode | Switch to normal quality, replace the cartridge, reprint |
| Thermal label comes out blank | Roll loaded with the coated face away from the print head, or wrong stock type | Flip the roll; confirm the stock is direct thermal |
| Half the label on one page, half on the next | Browser print preview paginating the PDF | Download the file and print from a PDF viewer instead of the browser tab |
The quickest diagnostic is holding the printout against a ruler: the wide barcode block should run its full intended width with crisp, separate bars. Anything compressed, broken or gray belongs in the recycling, because a code that struggles under your phone's camera will do worse on a conveyor scanner at 2 a.m.
Details that decide whether the label scans
Paper choice
Ordinary printer paper works when the print is dark and the sheet is taped flat with the barcode uncovered. Glossy photo stock is the one to avoid — inkjet ink beads and smears on it. The full plain-paper rules live in our regular paper guide.
Thermal media pairing
Direct thermal printers darken coated stock with heat and use no ink at all, so the wrong roll fails silently. Check the darkness setting when prints turn gray after years of service — heads age. Choosing hardware is covered in the thermal printer guide.
Placement after printing
A perfect print still fails wrapped around a box edge or under a strip of tape laid across the bars. Flat face, seams avoided, barcode naked — our label placement guide shows the layout.
Reprint, and the narrow case for voiding instead
A misprint changes nothing about the shipment record, so the remedy is mechanical: fix the setting, print the same file, throw away the failure. Where the label came from decides where that file lives — the purchase history at the carrier, the order page at a marketplace, or the label page linked from your receipt for purchases made here. The recovery paths for each are collected in our reprint guide.
Voiding enters only when the content is wrong rather than the printing — a mistyped address, an underdeclared weight, yesterday's service choice. Correcting content means canceling the old purchase inside the carrier's refund window and buying fresh, which is a different procedure with its own deadlines, laid out in the voiding guide. And a spare copy of a label whose parcel already shipped is scrap paper: one barcode, one box, always.
Misprint questions
Why is my shipping label printing too small?
The print dialog is scaling the page. Fit-to-page and shrink-to-fit settings compress the label and its barcode; setting the scale to 100 percent or actual size restores full dimensions. On thermal printers the same symptom means the driver thinks it holds letter paper instead of 4 x 6 stock.
Why does my thermal printer produce a blank label?
Nine times out of ten the roll is in backwards. Direct thermal stock prints only on its coated face - scratch it with a fingernail and the coated side shows a dark mark. Flip the roll so that face meets the print head. A roll of thermal-transfer stock in a direct thermal machine gives the same blank result.
Is it OK to write over or touch up a bad barcode with a pen?
No. Barcode readers measure the width of bars and gaps, and hand-drawn corrections change those widths into gibberish. A flawed barcode calls for a fresh print of the same file, which costs nothing, rather than repair work.
Do I need a new label after a misprint, or the same one again?
The same one. A misprint wastes paper, not postage, so print the identical file again and discard the bad copy. Only when the information itself is wrong - address, weight, service - does the label need voiding and repurchasing instead.