From: Dave Rose (cactuscowboy@bresnan.net)
Date: 07/24/03-07:36:40 PM Z
Greetings from Big Wonderful Wyoming,
As I'd surmised, the "dry dichro" technique appears to be another way of
controlling gum/dichromate/water ratios on a batch to batch basis. I've not
actually tried "dry dichro", but I have to believe that the same results can
be had with "wet dichro". Whether you initially mix dichromate powder into
gum or water should make no difference, assuming the final mixes are the
same. Are we not talking about different methods to achieve the same end
result?
Thank you Katherine for posting the link to my gallery on the
alternativephotography site. Here it is again:
http://www.alternativephotography.com/dave_rose.html
Although some of my gum exposures are made with saturated solutions of AD or
PD mixed 1:1 with gum (the 'traditional' formula), I'll often vary the
strength of the sensitizer solution and/or the ratio of sensitizer to gum as
need dictates. I think we can all agree that varying the ratios between
gum/pigment/dichromate/water has a significant impact on the results.
Utilizing the flexibility of the gum process to it's fullest advantage and
practicing superb technique can result in beautiful and finely detailed
prints.
While viscosity of the emulsion does affect its application, I believe that
expertise in brushing (or rolling) the emulsion onto the paper is more
important in achieving "extremely smooth coatings". If a thick, gum-heavy
emulsion is easier for some printers to work with, that's fine. I use
gum/sensitizer ratios ranging from 2:1 to 1:2. More often than not, the
coating is very smooth and even whatever the ratio used. I'm using wide
Hake brushes. I'm curious to know if anyone out there has tried using a
paint spray gun and air compressor to apply gum emulsion?
Sorry if I ruffled a few feathers with my post expressing annoyance at what
I perceived to be unwarranted "hype" over so-called "new" gum processes.
Excellent gum prints have been made for many years by dozens/hundreds? of
talented photographers. Alphonse Louis Poitevin observed the principle of
light acting upon chromated colloids in 1855. John Pouncy is credited with
developing the gum process around 1856. Gum over platinum was being done
100 years ago. Study the history of photography. Certainly techniques can
be refined and improved upon (as demonstrated by Stuart Melvin), but
ultimately the gum process remains much as it was during the past. Had
there not been such a plethora of soft, fuzzy and romantic gum prints made
during the heyday of pictorialism, gum might not have its undeserved
reputation as a low-resolution and muddy process. Can you imagine what
Weston and Adams might have done with gum printing during the F64 era?
As always, the discussions here about gum printing have been entertaining
and very informative. Welcome to the list Stuart, glad to have you join us.
Best regards,
Dave Rose
Powell, Wyoming
----- Original Message -----
From: "Katharine Thayer" <kthayer@pacifier.com>
To: <alt-photo-process-l@sask.usask.ca>
Sent: Thursday, July 24, 2003 12:03 AM
Subject: Re: Dry Dichromate and Gum, was Re: News from APIS
> Clay wrote:
> >
> . By
> > adding dry dichromate to the gum directly, you can greatly reduce the
> > total amount of water in the mix, and increase its viscosity, which can
> > lead to some extremely smooth coatings. This may not be something
> > desirable for everyone - I don't know.
>
> What you seem to be suggesting here is that smooth coatings are
> available only to people using less water, and that only those not
> caring about smooth coating would use more water, which is a false
> assumption on both counts. Dave Rose, I believe has told us that he uses
> both saturated ammonium and saturated potassium dichromates; a look at
> his straight gum prints should disabuse a person of the notion that one
> can't get smooth coatings using saturated dichromate in solution. (Sorry
> to keep using you as an example, Dave, but you're such a good example of
> the ideas I'm trying to get across.)
> Katharine Thayer
>
This archive was generated by hypermail 2.1.5 : 08/07/03-03:34:50 PM Z CST