How to print an A4 shipping label on a 4x6 thermal printer
Updated · Rotomal
First check whether the marketplace or carrier can produce a 4x6, 100x150 mm or A6 label directly; if it can, use that. If it only gives you an A4 or Letter page, crop the label area out of the PDF into a page of its own, print it at 100% (Actual size) with Fit to page turned off, and scan the barcode once before you ship. Scaling an A4 page down to 4x6 shrinks the barcode and can make it unreadable.
Step 1: look for a thermal format in the platform
- Shopify: shipping documents can be printed in Thermal (4 x 6 inch / 100 x 150 mm / A6), Letter or A4 format.
- eBay Germany: sellers on eBay's forum report that DHL labels are only offered as a DIN A4 page, unlike the US site; eBay's community team said it would pass the request to its shipping team again, without a date.
- Allegro Lokalnie: in a 2023 forum thread a moderator said 100x150 labels were not currently possible there.
- Other platforms: look for words like thermal, label printer, 4x6, A6 or ZPL in the label or print settings.
Know your label sizes
| Name | Size | Notes |
|---|---|---|
| 4x6 inch | 101.6 x 152.4 mm | Standard roll for US-style thermal printers |
| 100x150 mm | 100 x 150 mm | Common metric roll; nearly the same as 4x6 |
| A6 | 105 x 148 mm | A quarter of A4; slightly wider and shorter than 4x6 |
| A4 | 210 x 297 mm | Holds four A6 labels |
If the label is A6 and your roll is 4x6, the extra 3.4 mm of width may not fit. Check the label's printable content against the roll width before you buy rolls.
Step 2: crop the label out of the page
Any tool that can crop a PDF page works; paid PDF editors have a crop tool, and sellers on eBay's forum mention using one. A free route on Windows, macOS or Linux is Poppler's pdftoppm, which a German seller used to cut Hermes labels out of A4 pages: it renders a chosen rectangle of the page at a resolution you set. Measure the label's position once; carriers rarely move it.
# Render the top half of an A4 page at 300 dpi as a PNG
# A4 at 300 dpi is about 2480 x 3508 pixels
pdftoppm -r 300 -x 0 -y 0 -W 2480 -H 1754 -png label.pdf label-topA crop that keeps the PDF as vectors (changing the page's crop box) keeps text and barcodes sharper than an image crop. If you render to an image, use 300 dpi or more.
Step 3: print at true size
- Choose your label printer and the 4x6, 100x150 mm or A6 paper size in the print dialog.
- Set scale to 100% or Actual size and turn off Fit to page, Shrink oversized pages and headers or footers.
- Rotate to portrait if the label was landscape on the A4 page.
- Print one label and scan its barcode with a phone app before printing the batch.
If you want this done for you
Label Trim crops A4 and Letter labels from any carrier to 4x6, 100x150 mm or A6 in batches, keeps barcodes at their true size, checks they still scan and can add the packing slip after each label. Plans start at $4 a month.
Questions
Can I just print the A4 page with Fit to page?
It will print, but everything, including the barcode, is shrunk. Carriers may not be able to scan it. Crop instead of scaling.
Is 100x150 mm the same as 4x6?
Almost: 4x6 inch is 101.6 x 152.4 mm. Most labels designed for one print fine on the other at 100% scale.
Sources
- Shopify Help Center: printing shipping labels and documents Source: help.shopify.com
- eBay Germany community: 4x6 print format for shipping labels Source: community.ebay.de
- Allegro community: label formats ZPL or PDF 100x150 (2023) Source: spolecznosc.allegro.pl
- mikrocontroller.net forum: printing Hermes A4 labels on a Zebra printer (2023) Source: mikrocontroller.net