But more of an example as I didn't put my heart into this one
It also attempts to illustrate for Kaimarx that going w/o black isn't that big of a barrier. Of course if your duotone ink choices are both very light or very saturated, yes, it will be tough to work with.
Here's the final representation of the duotone image "printed" on pure white paper. I haven't printed the duotone, so I'm not sure how accurate this representation / preview is. Please ignore the nasty jpg artifacts in the sky. I made the duo tone starting with jpg original linked below. This duotone "uses" 2 inks: Pantone 1545C (a dark brown) and Pantone 2707C (a light blue) - no black. On a properly calibrated monitor, it will have an obvious blue tint and you should be able to identify the deep shadows colors as "warm, not black".
Here's a link to the original:
http://www.pbase.com/swengineer/image/72358208.jpg
Here's a small sized version of the B&W conversion I did to form the basis of the duotone. If you think the duotone looked like a B&W, this should prove to you it is not. If you still think the duotone looks B&W (and especially if you also think this image looks tinted) your monitor probably needs calibration:
Here's the "plate" for the Pantone 1545C (darker = more ink density):
Here's the "plate" for the pantone 2707C. (It uses a lot of ink relative to the 1545 plate):
Finally, here's a perpendicular gradient overlay of the two colors to illustrate how they mix and "print" on the paper. 1545C density goes 0 to 100% from top to bottom. 2707C density goes 0 to 100% from L to R. The UL corner is pure (paper) white. The LR corner is as close to black as this combo can make. It may looks as if the duotone image gets closer to black than this gradient. But that's just an illusion due to the
much higher local contrast in the duotone:
Comments are welcome. I'll submit a more serious entry at some point. Hope this serves to get or keep the ball rolling.
-Mark