I was just looking at some of Coburn's prints here...

http://www.geh.org/fm/coburn/yosemite/htmlsrc/hammond00002.html#67:0157:0087

at the bottom of the page there are two prints of the Devil's Slide apparently from the same negative that are printed as silver gelatin & gum platinum process. Is this gum process the same as the 'gum over' process that some are working with or is it a different process. If indeed Coburn's gum platinum process is different could someone kindly direct me to some technical information about it.... Cheers & thanks, Annie

Theres a very informative article about a studio that recently undertook the project of recreating these prints from the original negatives here: http://www.picture-box.com/coburn1.html

Annie,

i suspect they are the same process.

Until very recently, I never heard of the "gum-over platinum" process, only the "gum-platinum" process. However, some people (e.g., Terry King) are also now doing platinum-over-gum so I suspect the new label came about to differentiate between the two contemporary variations.

Joe

That was a good article, the photographs made it more obvious that it was most likely the gum-over as they utilized more pigments than the prints of Yosemite... the ones of Devil's Slide were so close in tonality I thought perhaps it was indeed something different... gum platinum certainly seems to offer a wide spectrum of subtle control of tone... I have got to make my way to some of the collections and see some originals!

I've had a copy of "5th Ave" printed as a silver image for years. Seeing it as a gum over platinum image was like seeing for the 1st time. And that Rodin image? He looks like he's coming off of the page. What a difference.