Surrendering to Shrinkage-- Thanks Denise!

[Katharine Thayer]

Hi All,
I've recently moved and am having to adjust to a different climate; my workshop is colder and drier than I've experienced before in the winter, and I'm finding I have to approach several parts of my process, including registration, differently.

Yesterday when I discovered that a print had shrunk past the point of registration, I first thought okay, I'll have to soak it again and start the drying process over again. But then I remembered Denise's innovation of printing the negative to match the paper rather than trying to match the paper to the negative. So I put the print on the scanner and let the scanner software measure it, then adjusted the size of the second negative to match the print. Printed it out, put it over the print, and it registered perfectly. Problem solved. Thanks Denise for a great idea!
Katharine

 

[E Thomson]

Question for Katherine...

I'm hoping you will see this reply many months later. I am slowly progressing in a project to set up for gum printing and am working with a photographer who mostly makes his living as a writer and historian of things photographic. We decided to go back to original sources and start from there, calibrating materials and process as carefully as we can.

In particular we are dissecting the second edition 1898 Maskell/Demachy text titled "Photo-Aquatint", looking at variations between it and an earlier edition.

From that and further readings I have been compiling a list of various "control elements," what you elegantly call the Dance of Interacting Variables. You got my attention with your discussion of how humidity affected your process and I had decided I needed to control for ambient moisture, perhaps with a humidifier in the studio.

Here's my question. You said in this post that you had moved to a drier climate. How has that affected your process? Have you needed to humidify the studio?

Thanks for any comments from anyone.

Eric

 

[Katharine Thayer]

reply re gum and humidity

Hi, I just happened to check in (50 unread posts!) and found your question, good timing.

I've not been printing much at all in the last year due to health problems, so I haven't been able to work on that problem very much and haven't settled on a final longterm solution. But a general answer to your question:

A decrease in humidity has two significant consequences: (1) it's more difficult to coat smoothly without adding water (which I don't like to do because of its desaturating effect on color) I personally think humidifying the paper may be the best solution, and that's what I'll be doing when I return to gum printing this summer. Keith Gerling humidifies his paper routinely and reports good results from this (you can probably find his site by googling his name and "gum"). I've also had some fairly good results from soaking paper and blotting dry before coating.

http://www.pacifier.com/~kthayer/html/wetcoat.html


(2) exposure time is increased. This of course can be handled easily by increasing the exposure time (using a step tablet to determine optimum exposure) to match the conditions.

You can't go far wrong with Machell/Demachy 1898; at least their observations match my own fairly closely in most of that paper, which I must say is not true of most of the historical recommendations I've seen; IMO most of those guys just didn't know what the heck they were talking about. Good luck, and don't hesitate to ask further questions.
Katharine