Move-O-Matic was an ADHD side quest whilst moving house to try and automate label printing using the awesome blabel to generate labels from HTML/CSS and Ghostscript to send the labels to my label printer.
I was using this for 50mmx30mm labels on an ancient Thermal Transfer Printer. Any size would work, the app uses blabel to create labels as PDF, then sends the PDF to a nominated printer using a cli call to Ghostscript. Be afraid, this is very crudely written, everything about it is shocking, but I'm currently midst move and it's working just dandy.
Hopefully this helps someone as well. PRs very welcome. Licence = MIT