Barcode printer ribbons: Coated side in vs. Coated side out
The “ink” (wax, wax-resin, etc.) coating on the a thermal barcode printer ribbon can be manufactured to face in or out on the roll.
Most brands of barcode label printer work with only coated side in or coated side out. Some printers support both.
Coated side out:
Most Zebra, Datamax, Intermec, Printronix and TEC printers
Coated side in:
Sato
Either:
Printronix T4M and SL4M