J2Chrono supports labeling using RFID printers. With RFID printer you can print and program RFID tags automatically and simultaneously.
For tag programming see: Programming a tag for J2Chrono timekeeping purposes
Zebra printers
ZPL templates
J2Chrono supports ZPL templates with three parameters named as follows:
epcdatahex: "00000001000000000000007B" epcdatadec: "123" othertext: "123 Jason Bourne"