Re: Getting back into Cyanotype (classic formula)

I don't double coat. The reason to mix 2:1 is it increases the speed of the
traditional formula. Apparently the more pot ferri you have the slower the
speed, if I remember correctly. One of the complaints about the traditional
formula is its slow speed, but with 2:1 I have 6 mn UV exposures.

I have not tried it the way you describe, in other words, mixing the
formulas at 40% FAC and 8% pot ferri and then using 1:1....maybe it is too
thick a solution, because as it is, a 20% solution is really a lot of FAC
powder. How about trying it and reporting your results?

But I didn't devise the formula, a guy named Schaefer did a lot of
experimentation with cyanotype and came up with that. And then Sam Wang
taught me this in grad school. He had a sheet comparing all the different
formulas on cyano floating around the universe, and it seems in general it
is a very flexible process.

I don't know the solubility of FAC, in other words, when does it fall out of
solution? A scientist on this list I'm sure can answer that.

I find with cyanotype that the real issue is creating the correct curve to
fit the short tonal scale.
Chris

----- Original Message -----
From: "Michael Koch-Schulte" <mkochsch@shaw.ca>
To: <alt-photo-process-l@sask.usask.ca>
Sent: Saturday, February 11, 2006 10:46 PM
Subject: Re: Getting back into Cyanotype (classic formula)

>
> ----- Original Message -----
> From: "Christina Z. Anderson" <zphoto@montana.net>
> To: <alt-photo-process-l@sask.usask.ca>
> Sent: Friday, February 10, 2006 2:31 PM
> Subject: Re: Getting back into Cyanotype (classic formula)
>
>
>> it works fine, Mac. weigh it and make a 20% solution, 20g to 100ml. I
> use
>> 8% pot ferri, but Sam Wang I think uses 10%. I also use it 2A:1B.
>
> Christina,
>
> Why do a 2:1 of part "A" to "B" why not just increase the weight by volume
> of part "A" or decrease the saturation of part "B". By going 2:1 aren't
> you
> in effect just diluting part "B"? Q: Are you double coating this mixture?
>
> ~m
>
Received on Sun Feb 12 09:23:20 2006