I have a quick question on something that has given me difficulty. I wrote a script and drew this coverpage- http://img709.imageshack.us/img709/996/thewrongcrowd.jpg
After a photoshoot, I attempted to create the same style using the filter sketch>note paper, which only allows 2 colors at a time, so I had to do two of them and blend them together for a semi crappy result- http://img301.imageshack.us/img301/6443/54041462077528752542738.jpg
Is there a better way I can achieve this look so that more detail can be shown through this tritone kind of style? I want to make the darks black, the highlights white, and everything in between red.