Zebra offers four print resolution upgrade kits. The upgrade procedure is the same for all four kits and they require changing both the printhead and platen / drive rollers (because they are print-resolution dependent). The printer automatically detects changes in the printheads. Platen roller materials are identifiable by color.
For standard printing, or for linerless printing (available only on ZD620 Direct Thermal printers), you can change the print resolution from:
203 dpi to 300 dpi
300 dpi to 203 dpi
Printheads provided with the upgrade kits include a 203 or 300 marking to help you keep the upgrade printhead separate from the original printhead. The original printhead contains no marking identifying its print resolution.
The platen (drive) rollers are colored differently to help you keep from accidentally using the old platen roller. See Identifying Platen Drive Rollers Types.