[alt-photo] Re: back to the flaking/speckling question

[Kurt Nagy]

I use a formula I found in the archives here.  I mix a 3:1 of gum/pigment as a stock solution that I then pull from when mixing my coating solution.



On Nov 21, 2011, at 2:49 PM, "Julian Smart" <juliansmart at virginmedia.com> wrote:

> Hi Paul, perhaps I should have phrased my question slightly differently.
> 
> I know all the variables relating to pigment concentration in the mix. What I don't understand is how you quantify a ratio. I personally just squeeze out a worm of pigment onto a saucer, then add 5ml of gum. The amount I squeeze out is usually down to experience and will vary according to the exact pigment and the contrast I am after. The ratio of pigment in the gum emulsion will therefore vary but there is always 5ml of gum in there.
> 
> In order to have a quantifiable  pigment/gum ratio, one would have to weigh the pigment out and then assign a "strength" value to the mix. This would be easy to do if one were to mix up an entire tube of pigment with gum, as a stock solution- I know a lot of printers do just this, especially those practicing 4 colour gums as the necessary consistency would be there. Perhaps this is what you do?
> 
> Julian.
> 
> 
> 
> ----- Original Message ----- From: "Paul Viapiano" <viapiano at pacbell.net>
> To: "The alternative photographic processes mailing list" <alt-photo-process-list at lists.altphotolist.org>
> Sent: Monday, November 21, 2011 8:01 PM
> Subject: [alt-photo] Re: back to the flaking/speckling question
> 
> 
>> Well, it depends on how much saturation you're looking for vs flaking problems vs the number of layers you anticipate putting down...for tricolors I have a specific ratio I like for *my* methods and *my* negatives. It'll be different for everyone...for single neg multi layer gums I experiment a lot, but since I've put the time in to learn the process and kept really good notes along the way, I'm able to have more confidence.
>> 
>> I don't like to use water in my mixture, so I look at the gum/pigment ratio as a way to control the saturation, and realize that once developed, gum will tend to look less saturated than you expect. Of course, your dichromate ratio willl have a say in that as well...
>> 
>> It took me a year of solid printing to nail all my variables down, or at least understand them a lot better and have a more reasonable expectation of the outcome, or at least how to push the print in a certain direction. But then, gum isn't usually about control...which can be it's charm.
>> 
>> Paul
>> 
>> 
>> 
>> 
>> ----- Original Message ----- From: "Julian Smart" <juliansmart at virginmedia.com>
>> To: "The alternative photographic processes mailing list" <alt-photo-process-list at lists.altphotolist.org>
>> Sent: Monday, November 21, 2011 11:02 AM
>> Subject: [alt-photo] Re: back to the flaking/speckling question
>> 
>> 
>>> This has been puzzling me since the first posting in this thread. Forgive me for my ignorance but how do you arrive at a gum/pigment ratio?
>>> 
>>> ----- Original Message ----- From: "Paul Viapiano" <viapiano at pacbell.net>
>>> To: "The alternative photographic processes mailing list" <alt-photo-process-list at lists.altphotolist.org>
>>> Sent: Monday, November 21, 2011 5:47 PM
>>> Subject: [alt-photo] Re: back to the flaking/speckling question
>>> 
>>> 
>>>> What's your gum/pigment ratio on the affected print?
>>>> 
>>>> 
>>>> 
>>> 
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