Re: GUM PRINTING QUESTION

Hamish Stewart wrote:
>
> Hello to all the gum printers on the list!
>
> I have a question related to clearing of the dichromate stain at the end of
> the final printing.
>
> Does the clearing increase the archival properties of gum prints or is the
> clearing process essentially to remove any residual dichromate stain?
>
> I have undertaken the clearing process as a matter of course though I have
> not run into any issues with any noticeable dichromate stain for some time.
> Can I safely omit this step?
>
> Regards from sunny London
>
> Hamish Stewart Gum Bichromate Photographer - http://www.gumphoto.co.uk

Hi Hamish,
I have never cleared except in the rare instance when I've encountered
actual stain. Then I have cleared, but more for the appearance of the
print than for the archivality. On one hand I've always sort of believed
what I read about this, that stain left in the paper could compromise
the paper, but on the other hand I don't really know if that is true or
not, and at the same time I've never been one to believe that one should
clear even if there's no stain there.

When I was experimenting with exposing unpigmented dichromated gum on
mylar for research purposes, I found that printing the way I ordinarily
print, the hardened and dried gum was absolutely crystal clear,
colorless. But if I cleared the hardened gum, then it turned light blue.
And if I printed to the point of dichromate stain and then cleared it,
then the cleared hardened gum was REALLY blue. The blue color was not
eliminated by a water bath after the clearing step. So that experience
has convinced me that I get the very cleanest gum by not clearing.

Obviously opinions and observations differ on this question.
Katharine
Received on Mon Aug 8 22:16:19 2005