I tried Eagle 5.11 on Windows XP, 6.1 on Mac Lion, and Windows XP.. Closed all layers but top layer.. The results are the same on Xerox 3140 printer.. Eagle prints everything a little thicker. The pads of MLF package bridges, and the 10mil lines between SO8 package's pins 1 and 2 tends to bridge to the pin 1.. The calibration is OK, I printed 100mm x 100mm rectangle and its good enough..
I printed to pdf, and printed the pdf with Preview application on macosx, this time the results are much better.. I would say "Oh, I can do that way" but after comparing it with the same packaging, same size that Proteus Ares produces, I saw that Proteus produces cleaner results.. It looks like Eagle widens everything..
Should I configure anything other than "calibrate" and "black" options on printer dialog?