For continuous media, enter the JOURNAL command. The CPCL manual explains that JOURNAL disables the printer's automatic alignment feature which searches for bars/gaps with which to align.
Journal/Continuous Media (receipt type paper with no breaks in the roll):
! DF CONFIG.SYS
! UTILITIES
JOURNAL
PRINT
The next file that gets sent actually calibrates the printer's sensors to the installed media so that it knows the appropriate label length. When this file is sent to the printer the printer will feed a few labels out to recalibrate: