My thermal label quality is bad
Check out the Zebra support article below regarding Print Quality Issues.
https://supportcommunity.zebra.com/s/article/ZP-Series--Resolving-Print-Quality-Issues
Incorrect printer settings or a dirty print head can cause print quality issues. We recommend doing a factory reset on your printer and then printing a test page to see if quality issues continue.
Have you tried cleaning your printhead? We recommend using these cleaning pens periodically for best output.