To the OP, thanks a million. If we ever cross wakes, the beers are on me.
I have, well work has, a HP DesignJet 450C inkjet plotter that uses rolls of paper 24 inches wide. When I print some charts the text on the legend, compass rose and notes are impossible to read. I don't know if resolution is lost during the conversion from bsb to png to plotter lingo of HPGL. Any ideas?
BSB is a compressed raster format as is png but png is lossless so you are unlikely to have any problem there unless you change resolutions. HPGL is a vector language so you are dependent on the translation there. My suggestion is that you edit (crop) the png file so that you can print just the compass rose on a raster printer (inkjet or laser) so you know if that file is OK. If it is, they you would need to find another way to do the conversion to HPGL. If it isn't, then look the other way.