We are still in contact with the vendor of the printer to work out
the problem. As we also have better results with the Gutenprint
driver for this particular printer under Mac OSX, we are quite
shure, that there is a problem with the actual Mac OSX driver.
With what particular driver and printer?
Our interest actually is to know, if other people also made the
experience about different quality in printer drivers betweeen Mac
OSX and Windows or if we have may discovered it the first time...
When I have compared them (Mac and PC drivers on various printers
over the years) I have not seen such a difference. Thus it would be
nice to know with what printer you are seeing the difference.