Digital BW, The Print

Photogravure is an "Intaglio" process...if you're doing research that 
will help.  Etching, engravings, mezzotint, etc. are subgroups of 
intaglio, as is photogravure I believe.

Quick google search kicked this link up...which I felt acurrate 
enough to pass on...
http://www.kamprint.com/printmak.htm

Thought this one might amuse some as well...
http://www.mtsu.edu/~art/printmaking/imagon.html

One of the criticisms of photographers is that they do not study the 
whole of the history of art...afraid this thread confirms that 
fallacy (maybe it's just my momentary mood).  You can learn as much 
about lighting a scene by studying Rembrandt as Karsh.

Sincerely,
Cleavis