Thermal 4 × 6 in or Letter paper: choosing how to print shipping labels
Last updated October 28, 2026
You can print carrier labels on a thermal label printer or on an ordinary laser or inkjet printer. Carrier help pages describe both. Here is how to choose, and what changes in your PDF workflow.
What the carriers say
- USPS (Click-N-Ship help): use a laser printer or a high-quality inkjet (600 dpi recommended for inkjet); labels should print to approximately 4 × 6 in; plain paper is acceptable; do not tape over the Postal Use area or cover the barcodes.
- UPS: thermal label printers that print 4 × 6 in are supported, and standard laser and inkjet printers are also supported. Label stock choices in UPS's WorldShip help include thermal 4 × 6 and 4 × 6¼ in, and laser 8.5 × 11 in with 1, 2 or 4 labels per page, plus laser A4.
- FedEx: its printer guidance says labels printed on plain paper and covered with tape or put in plastic pouches can damage scanning ability, and that the standard label stock is 4 × 6.75 in. Barcodes need at least 0.10 in of clear space on all sides.
Thermal 4 × 6 in
- Pros: no ink; one label per sheet, peel and stick; labels come out at the size carriers expect.
- Cons: you buy a printer and label rolls; it only prints labels (and small slips).
- Set the paper size to 4 × 6 in in your PDF viewer's printer settings, and print at Actual size.
Letter (or A4) on a laser or inkjet printer
- Pros: no new hardware; use full-sheet adhesive labels, half-sheet labels or plain paper with clear tape only on the edges (never over a barcode).
- Cons: wasteful if you print one label per sheet; print quality depends on your printer and stock, so test-scan.
- To avoid waste, put two labels on a sheet at their real size. See our guide on fitting two labels on one sheet.
Either way
- Print at 100% / Actual size. Never use “Fit” or “Shrink to fit”.
- Print one test label and scan it before a batch.
- Do not cover barcodes with tape or a plastic sleeve unless your carrier says it is acceptable.
- Keep the carrier's own label unaltered: do not edit its content.
If you already have a label as a Letter-page PDF but want it on 4 × 6 in stock (or the reverse), Labelloom can re-flow the page to a different sheet size without scaling it. Check the carrier's current requirements for your service first; they change.
Sources
- USPS, "Click-N-Ship — The Basics" (FAQ), "Before you print": https://faq.usps.com/articles/Knowledge/Click-N-Ship-The-Basics (read 2026-10-28)
- UPS, "Thermal printing of labels": https://www.ups.com/us/en/support/shipping-support/print-shipping-labels/thermal-printing-of-labels (read 2026-10-27 as a search-index excerpt; ups.com blocks automated fetching)
- UPS, "Set the Label Stock Configuration" (PDF): https://www.ups.com/assets/resources/webcontent/en_US/LabelPrinterPreferences.pdf (read 2026-10-28)
- FedEx, "Printer maintenance guidelines" (PDF, last update February 20, 2023 per the document): https://www.fedex.com/content/dam/fedex/us-united-states/shipping/images/printer_maintenance_guidelines.pdf (read 2026-10-28)
Related tool: Labelloom. Estimates and guidance only; check the source documents before relying on a figure.