01
First — 203 dpi or 300 dpi
203 dpi covers the great majority of warehouse work: carton labels, pallet labels, anything read by a scanner across a dock. 300 dpi is for small type and dense codes on a label that is already crowded — compliance labels, or a 2D code that has to hold a lot in a small square. Paying for 300 when 203 would do buys you nothing a scanner can see.
02
Second — does it peel and rewind?
Standard, and the label comes out to be torn off. Peel with full rewind separates the label from its backing as it prints and winds the liner up inside, so an operator takes a label that is ready to apply rather than peeling it themselves. On a line where somebody labels a carton every few seconds, that is the difference.
03
The second one cannot be added later
Zebra fits peel and rewind at the factory only. Connectivity and RFID can be added to a ZT421 in the field; this cannot. So it is the one decision on this page worth being sure about, because changing your mind means changing the printer.
It runs both kinds of label, and that is not obvious from the price list. Every industrial printer does direct thermal and thermal transfer both — the ribbon is loaded or it is not, and the machine does not care. So this is not the commitment to buying ribbons forever that it looks like. Put ribbon-free stock in it for the despatch labels that get read once and thrown away, load a ribbon for the ones that have to last a year, and it is the same printer either way. The labels page is where that choice actually gets made.
Six inches is the whole reason to be on this page. If your labels are four inches or narrower, a ZD421 does the job for a fraction of this and we would rather sell you that. This printer earns the difference on width, on a metal frame that survives a warehouse, and on a media path that takes a 203 mm roll and a 450 m ribbon — an industrial printer makes its money by not stopping, and most of what stops a desktop machine is running out. Worth knowing before assuming wider is better: the four inch ZT411 is the faster of the two, and 600 dpi is available there and not here.