Install on ShopifyOnce you ship more than a few packages a day, cutting and taping paper labels gets old. Most sellers move to a thermal label printer and 4×6 inch labels: one sticker per package, no ink, no trimming. Here's what the words on the box of labels mean.
Why 4×6
4 × 6 inches (100 × 150 mm, also listed as A6) is the standard size for shipping labels printed on a label printer. Shopify lists it as the thermal page size for label printers, and UPS says ups.com works with most thermal label printers that print 4" × 6" labels. If you buy one size of label stock, buy this one.
Direct thermal vs thermal transfer
Direct thermal printers use heat-sensitive labels. The printhead heats the spots that should be black; there's no ribbon, ink or toner. The catch: direct thermal labels react to their surroundings. Too much heat or sunlight can darken them until the text or barcode is hard to read. That's fine for something that only has to last until delivery, and printer maker Zebra names shipping labels and receipts as ideal uses.
Thermal transfer printers melt ink from a ribbon onto the label. The print lasts much longer and can't be rubbed off, which is why it's used for product and asset labels. You also buy and change ribbons.
For shipping labels, direct thermal is the usual choice. Keep blank labels and labeled packages out of strong heat and direct sun, like a hot car.
Fanfold vs roll
Same labels, packed two ways:
- Roll: labels wound around a cardboard core. The roll sits on a holder in or behind the printer. Check two numbers in your printer's manual: the core size it takes and the largest roll it fits.
- Fanfold: a stack folded back and forth along the perforations. It usually feeds from behind or under the printer, needs no holder, stores flat and shows at a glance how many are left.
Neither is better. Buy what your printer accepts and what fits your desk.
A short label-stock checklist
- Size: 4 × 6 inches.
- Type: direct thermal, unless your printer is set up for ribbons.
- Perforated between labels, so they tear off cleanly.
- Fits your printer: label width, core size or fanfold feed, as listed in the manual.
- Calibrate after loading new stock. Label printers find the start of each label by sensing the gap (or a black mark) between labels. Run the calibration in your printer's manual so labels don't print across the gap.
PDF or ZPL?
Shipping tools usually hand you labels in one of two formats:
- PDF: printed through your computer's printer driver, like any document. Choose the 4 × 6 page size and print at 100% (actual size), not "fit to page", so the barcode isn't scaled.
- ZPL: the Zebra Programming Language, a set of text commands that many thermal printers read directly. The printer draws the label itself from those commands. Use it only if your printer supports ZPL.
If you aren't sure, start with PDF. It works with any printer that has a driver.
No label printer yet?
A regular printer works. Shopify offers a Letter (8.5 × 11 inch) page size for desktop printers, and UPS supports standard desktop laser and inkjet printers. Pick the page size that matches the printer you're using. Trim the label and tape it flat. And if you have no printer at all, USPS can print the label for you: how to ship without a printer.
Printing labels in Muvo
Muvo prints the whole batch in one file, in order, in the format you choose: 4×6 thermal (PDF or ZPL), regular 8.5 × 11 paper, or USPS QR codes when there's no printer at all. Set your printer once in Settings. Lost a label? Every batch file stays in Orders, under Printed, so you can print it again.
Muvo has no monthly fee on the Free plan. See pricing for the label fee and what Pro adds, or create a free account and connect your store.
Sources: Shopify Help Center, Printing shipping labels and shipping documents and Supported shipping label printers; UPS, Thermal printing of labels; Zebra, Direct thermal and thermal transfer printing. Check your printer's manual for the stock it supports.
