Digital BW, The Print

AFAIK, 100 just retains the original luminescence...higher than 100 the image will be brighter, lower it will be darker.  



> Use the Photoshop Channel Mixer.  Click on monochrome.  Adust red to 
> +160, green to +140, and blue to minus 200.  You can tweak these 
> adjustments, of course, trying to stick to a total of 100.  (Why 100 
> is such a magical number, I don't know.  Would welcome an 
> explanation).
> 
> 
> Norm