In general, most barcode printers can support both internal and external carbon in the barcode carbon band, but not all barcode printers can use both internal and external carbon. So you have to make your own judgment about what's inside and what's outside.
Distinguish the barcode carbon belt is the internal and external carbon, tore down a self-adhesive label, to bring a stick carbon, and then see if gum by carbon tape on it, if you have, that which is with carbon powder surface carbon belt, carbon, with another side is not then look at the volume of carbon belt way, you'll know is inside outside carbon or carbon.