For some reason, Gutenprint-5.1.7 is creating binary PCL-like print
files instead of Postscript output. Gimp is at 2.4.6 on FBSD-7.0.

When trying to manually compile Gutenprint, it appears that most of the
"drivers" are disabled (I don't use CUPS so that doesn't matter):

Release: gutenprint 5.1.7 generated on 05 Mar 2008

Features:
Build CUPS: no
Build Ghostscript IJS driver: no
Build Foomatic data: no
Build enhanced Print plugin for GIMP: no
Build EPSON Stylus utility: yes
Build test programs: yes
Build testpattern generator: yes

No amount of configuration settings or including Foomatic/IJS or not,
have made any difference: output is always binary "raw" data (which if
sent to the proper "raw" laser printer port will print, but this is not
desired).