I'm using Labview 6.1 and when plotting an X/Y plot in the linear mode, no vertical lines appear in the plot. This happens with both of my HP 2100M and HP 4V laserjet printers. The Lines are also a bit on the light side.
Have you tried using a different color for the major and minor axes of the graph? How are you prining the graph? Are you doing this programatically or are you doing this with the file >> print method? Finally there have been several threads lately on printing. You may want to take a look at their methods.
