I have two printers. An Epson R2400 and a HP 7160. Each uses two types of black ink and two types of gray. I may have to replace the R2400 because no one seems to be able to fix it. I used to have a Canon s900 and liked it, so I'm looking at Canon's PRO9000 as a possible replacement. Here's what I don't get. As I mentioned before my printers use two types each of black and gray ink. The reviews I read praise the results of color prints, B&W prints and text of the PRO9000. Now this printer uses only one type of black and no gray inks. How does it do such an all around good job with only the one type of black?