During usage of print/cups PageLog remains empty. ErrorLog and AccessLog are filled as expected. Otherwise printing works correctly. Issue is discussed on the list: http://lists.freebsd.org/pipermail/freebsd-ports/2015-August/100186.html I have tested on 10.2-RELEASE-p1 (amd64).
You have to set PageLogFormat in /usr/local/etc/cups/cupsd.conf. See man cupsd.conf