A rip can send data streams in individual channels. Most rips have 4 channel control ie, CMYK. The base of printers before the Z or Canon pigments were CMYK with varying densities of the CMYK primaries. With this control you can print only K for example and or with small amounts of composite to increase density where needed. You can print B&W on the dye printers through a standard driver (all systems to date send only three channel data stream) but there will be some color cast or bi or tri-toning. The stock profiles are built around essentially the color mapping and the grayscale is only a smaller part of that build. What I have been doing for some time is hacking the rgb profiles , to make a gray balance that is intended only for B&W prints through the driver. I could do this through the rip which makes it a lot easier, but fact is most people don¹t want to use a rip. So a edit and save out edit lists, send off a profile, and edit according to the results the user sees. Not scientific at all, but this unorthodox hacking results in some decent B&W output from DJ printers. If you need to do a lot of B&W printing I suggest ImagePrint. I don¹t like their stock B&W profiles, but when you modify the white point you can get better results than a hacked profile. Look on my site for more info.
-- Neil Snape photographer Paris France [EMAIL PROTECTED] http://www.neilsnape.com
