We need also to introduce a UDEV rule which makes the /dev/bus/usb/*/* files being owned by the "lp" group for all printers (not only HP). Currently this is only set for HP printers by /lib/udev/rules.d/40-hplip.rules. We must add something apprpriate to for example /lib/udev/rules.d/50-udev-default.rules but valid for all printers.
We need also to introduce a UDEV rule which makes the /dev/bus/usb/*/* files being owned by the "lp" group for all printers (not only HP). Currently this is only set for HP printers by /lib/udev/ rules.d/ 40-hplip. rules. We must add something apprpriate to for example /lib/udev/ rules.d/ 50-udev- default. rules but valid for all printers.