U of S | Mailing List Archive | alt-photo-process-l | Re: Dark reaction

Re: Dark reaction

In copper plate photgravure, they often senstize the gelatin tissue with dichromate then store it in a refrigerator until they use it. I am not sure how long it keeps.

Mark Nelson

www.PrecisionDigitalNegatives.com, PDNPrintForum@YahooGroups, www.MarkINelsonPhoto.com , sent from my iPhonetypeDeviceThingy

On Oct 29, 2009, at 2:44 PM, etienne garbaux <photographeur@nerdshack.com > wrote:

Katharine wrote:

As noted, Kosar is fairly
good on the dark reaction, except that the literature Kosar reviews
and summarizes is almost entirely related to dichromated gelatin,
which isn't precisely equivalent to dichromated gum. Studies on
dichromated PVA give a closer approximation to the mechanisms  of
dichromated gum arabic, and very occasionally, one can even find
direct studies of dichromated gum, as the one cited above.
Good point about Kosar. I have found his book immensely helpful in getting the most out of the carbon process, but other colloids do not act the same as gelatin.

Best regards,