The Rollo Wireless X1040 and the DYMO LabelWriter 5XL are both capable 4-inch, direct-thermal printers (no ink or toner) that crank out carrier-ready labels for USPS, UPS, FedEx, and more.
Two favorites for 4×6 shipping labels are the Rollo Wireless X1040 and the Brother QL-1110NWB. Both are direct-thermal (inkless), both can print wide labels used by USPS/UPS/FedEx, and both have strong ecosystems.
If you’re choosing a label printer for Etsy, eBay, or Shopify shipping, the Rollo Wireless X1040 and the MUNBYN RealWriter 403B are two of the most popular 4×6 direct-thermal models.