Discussing The Colours of Black & White Part I - Introduction in hatphoto.nomagicpill.org. Victor W. says: Introduction - Circumventing the issues that surround digital black and white imagery, namely the problems with limited shades, (256 of them).
You will need an edit suite than utilises layers such as Paintshop or Photoshop. Unfortunately I have not managed to port these ideas to free software such as GIMP due to the restricted layers tools. Photo DIY.