I’ve been building Print-Air—a small ESP32-S3 device that connects a USB label printer to Wi-Fi, letting you print from your iPhone using AirPrint or create labels through a web page. The web app includes: - Post-to and return-address templates - A saved default return address - An address book for regular recipients - Label size controls and printer status - Light and dark themes So far, I’ve tested it successfully with the DYMO LabelWriter 4XL and Brother QL-560. Other printer profiles are included as experimental support, but haven’t been hardware-tested yet. I’ve put together a DIY package with the firmware, Windows and Mac installer launchers, Arduino IDE instructions, full source code and a slim 3D-printable case with recessed Print-Air branding. It’s built around a specific ESP32-S3 board with 16 MB flash and 8 MB PSRAM—check the included guide before buying parts. Still a work in progress: normal iPhone AirPrint and web labels work on the tested printers, but Square POS receipt printing remains unresolved. A useful little project for anyone who wants to give an existing USB label printer wireless printing. What printer would you want to try it with?