Why is the sheet printed as a raster rather than line art?
The sheets are all CMYK, a substractive (“passive” if you like) color system. Normally all printers understand CMYK. Some though use a RGB color conversion, rendering the black (K=100) as an RGB value, which ist not really possible. This way black becomes a very dark grey, that is black mixed of red, green and blue, causing some laser printers to raster the line art, the only way laser printers can print grey. The best solution is to somehow set the printer drivers to print in CMYK, that should definately do the trick. A decent printer will be able to handle this task, if at all neccessary.
