It's hard to wrap your head around not coloring in something that usually is colored and vice-versa. I've tried a couple other times to duplicate this method, but so far, it looks like this was a fluke of luck as the other pieces haven't come out anything near what I pulled off here. 
Yeah, and it's tricky to know when to just let black flow into black. The art I did recently, some of it was in the style of Ted Naifeh, who does the Courtney Crumrin comics. You should look him up online, he's very good at that style of hard-edged black and white.
Ironically, I've never been much of a comic reader, but after seeing your art, I will certainly do a search and take a look at Naifeh's work. Thanks for the tip!
Courtney Crumrin is a good comic, my girlfriend got me into it. I like his artistic style though, the subject matter isn't remotely film noir, but the technique works well for that.
I agree the technique fits the subject quite well. I haven't had a chance yet to look into Courtney Crumrin, but I'll take a look into it once I get the chance to.