Desktop thermal transfer printer with UPS Worldship support. These things are reliable, printed several labels a week for a few years after buying it used. Thermal transfer device can get dust on it and need to be wiped off occasionally.

Linux

2020 Update: CUPS has updated and the options below are no longer necessary. Simply setup with EPL2 driver and go.

Old info:
Linux support is frustating but completely fixable. The printer will print out of the box with Zebra ZPL print driver. The prints will look poor and barcodes will be terrible and likely unreadable. The fix is to use the CenterOfPixel option when printing :
lpr -P printer -o CenterOfPixel pathtofile.
Prints will look just like they do on Windows. You can add this option as default in the .ppd file in /etc/cups/ppd for this printer by adding

*OpenUI *CenterOfPixel/Center Of Pixel: PickOne
*OrderDependency: 20 AnySetup *CenterOfPixel
*DefaultCenterOfPixel: true
*CenterOfPixel true/true: “”
*CenterOfPixel false/false: “”
*CloseUI: *CenterOfPixel

to the .ppd file.
/oldinfo

UPS

Printing UPS labels from a browser using UPS Thermal Printing Script requires the printer is setup with a raw queue. When adding the printer, click on generic driver then raw. Print normally and the script will take care of the rest. Label prints perfectly.

Verdict

Printer is dead reliable, supported by Linux