Mike wrote:

A client has asked me about removing stain marks from an old

photograph (a

sepia toned one)...

You might find your answer by simply examining the channels. A dark
stain might be confined to the blue channel of an RGB file (if you have
to, it might be worth converting into RGB if it is a CMYK file) If this
is the case you can reconstruct a neutral gray version of the image
using the Channel Mixer to exclude the blue channel (50% R & 50% G only-
Monochrome check box checked) This neutral version can then be colorized
to the original sepia tone any number of ways. A simple method might be
to sample the color from the original and fill a color layer with it to
colorize the neutral gray image.

--
Regards,

Lee Varis
varis@varis.com
http://www.varis.com
888-964-0024