A big question needing a *lot* of explanation. My best advice is to read
as many original sources as possible. It has become clear to me that no
one text has all the answers to this difficult process. Here is a
bibliography I suggest. Hope you live in area where these books can be
accessed. Research would be much simpler if Luis Nadeau had a book on this
subject ;-)
Bennett, Colin N. Elements of Photogravure: Photo Printing from Copper
Plates. 2nd Edition, Boston: American Photographic Publishing Co.,1927.
Cartwright, H. Mills. Photogravure: A Text Book on the Machine and
Hand-Printed Processes. 2nd Edition, Boston: American Photographic
Publishing Co.,1939.
Crawford, William. The Keepers of Light: A History and Working Guide to
Early Photographic Processes. Dobbs Ferry, New York: Morgan & Morgan. 1979.
Denison, Herbert. A Treatise on Photogravure. London: Ififfe and
Sons,1895. reprinted Rochester, N. Y.: Visual Studies Workshop, 1974.
Gassan, Arnold. Handbook for Contemporary Photography. 4th edition,
Rochester, New York: Light Impressions, 1977. (ISBN 0-87992-008-4)
Kolb, Gary P. Photogravure: A Process Handbook. Carbondale and
Edwardsville: Southern Illinois University Press, 1986. (ISBN 0-8093-1252-2)
Rothberg, Samuel W. (Sandy). Photogravure Handbook. Chicago: Privately
published technical manual, 1976.
Sacilotto, Deli. Photographic Printmaking Techniques. New York:
Watson-Guptill Publications, 1982. (ISBN 0-8230-4006-2)