Re: report on cynotype and acid and a chemistry question.

Carmen and Tom

I do not take credit for the 2A:1B; this is a formula from Sam Wang, who
prints incredible cyanotypes. Sam, in turn, learned it from another bigwig
whose name I cannot remember. Both Sam and this guy did extensive testing of
the different formulae and this was their finding. Maybe Sam will chime in
here with who the guy was. My exposures under UVBL are about 6 minutes.

I have not experienced any bleeding at all in the darks so I'm not sure why
James suggests this. However, I no longer use, nor need, any citric acid or
vinegar or those kinds of things. Vinegar just ended up mordanting the
cyanotype to my bathtub, my trays, my everything (I was going to say "nuts"
but I held myself back).
Chris
PS Carmen, I understand the 10 hour teaching day thing. I have been pushing
that for 9 weeks now...luckily my fridays are free to play catchup and also
print!

----- Original Message -----
From: "Carmen Lizardo" <carmenlizardo@yahoo.com>
To: <alt-photo-process-l@sask.usask.ca>
Sent: Thursday, October 27, 2005 7:48 PM
Subject: Re: report on cynotype and acid and a chemistry question.

> Dear Tom,
> Sorry I took so long before answering your message,
> I've been teaching 10 hours days the last 3 days and
> my mind is in another planet...
> No, your question was not unclear, I am just tired...
> My stock solution is: 100 grams of ferric ammonium
> citrate to 500 ml of water and 40gr of potassium
> ferric cyanide to 500ml of water.
> II am doubling the ferric citrate, because my printing
> times were very long and Christina suggested for me to
> do that. I believe that she has been using cyano this
> way for tri-color gum. Since she is so knowledgeable
> and helpful, I believe that she will have a much
> precise answer for you.
> Combining the chemicals this way and with the addition
> of the citric acid, works for me; (better contrast,
> d-max, tonal rage and shorter exposures) but I read
> somewhere, I think it was the Christopher James book
> that doubling the Ferric citrate could cause bleeding
> of the shadows...
> Let me know how it works for you, if you decide to try
> it,
> :-)
> Carmen
>
>
> --- "T. E. Andersen" <postlister@microscopica.com>
> wrote:
>
>> Thank you Carmen,
>>
>> It seems my question was a bit unclear. I meant the
>> actual recipe. Am I
>> to understand that you use these amounts of
>> solutions containing
>> "standard" concentrations of the two chemicals (i.e.
>> something in the
>> order of ~25% ferriammoniumcitrate and ~12.5%
>> potassiumferricyanide in
>> the stock solutions)?
>>
>> If I have understood this correctly, my next
>> question is: Why are you
>> doubling the amount of ferriammoniumcitrate?
>>
>> Tom Einar
>>
>>
>>
>> Carmen Lizardo wrote:
>> > Tom, I used 20ml of ferric ammonium citrate
>> solution,
>> > 10ml of potassium ferric cyanide and 5 ml of
>> citric
>> > acid.
>> > I diluted 40 grams of citric acid in 100ml of
>> > distilled water.
>> >
>> > Carmen
>> >
>> >
>> >
>> > --- "T. E. Andersen" <postlister@microscopica.com>
>> > wrote:
>> >
>> >
>> >>Hello Carmen,
>> >>
>> >>Thank you for the information on using citric acid
>> >>in the cyanotype
>> >>sensitizer.
>> >>The information you give about your recipe puzzles
>> >>me a bit. Could you
>> >>please post your actual recipe? The one I've
>> always
>> >>used, as well as all
>> >>other that I have checked, use a 1:1 ratio of the
>> >>two component
>> >>solutions. This implies that you may have a
>> >>significantly different
>> >>recipe from what I'm used to.
>> >>
>> >>Also,- when you say 25% citric acid, what do you
>> >>mean? Is it 25% of the
>> >>total volume? 25% by weight of citric acid in the
>> >>final solution?
>> >>
>> >>Thanks again, and have a fine day!
>> >>
>> >>Best regards,
>> >>Tom Einar Andersen
>> >>
>> >>
>> >>
>> >>Carmen Lizardo wrote:
>> >>
>> >>>I used the classic formula, mixed 2a: 1b and
>> added
>> >>
>> >>25
>> >>
>> >>>percent of citric acid (Of a 40 percent solution
>> >>
>> >>of
>> >>
>> >>>citric acid mixed with distilled water).
>> >>
>> >
>> >
>> >
>> >
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>
>
>
>
>
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Received on Thu Oct 27 20:14:01 2005