[Alt-photo] Argyrotype on Fabriano Artistico Extra White Soft Press 300gsm (140lb)

[Loris Medici]

Hi all,

For the last couple of days I was dealing with the calibration of
Argyrotype process on Fabriano Artistico Extra White Soft Press 300gsm
(140lb) paper (FAEW onwards...) acidified with sulfamic acid and wanted to
share few notes for the records.

I was having bleeding, grainness and all kinds of other problems with this
paper / sensitizer combination, no matter how much Tween I was using.

This paper has a remarkable amount of AKD sizing which makes application of
the Argyrotype sensitizer pretty problematic. As you may already know,
Argyrotype doesn't get easily absorbed into the paper's fibers easily,
probably because it has a significant amount of ammonium iron(III) citrate
(AFC onwards...) in the formula. Somehow, when the AFC content in the
solution increases, the paper is less and less inclined to accept it
readily. That's why it is advised to (additionally) use a surfactant such
as Tween 20, in order to facilitate the take up of the emulsion into the
paper's fibers.

When you compare the AFC content of Argyrotype against some other
sensitizers with it - which normally don't need any surfactant to work nice
- you notice an interesting condition:


AFC % AgNO3 %  Argyrotype 22 10.3  Trad. cyanotype (1+1) 10 - 12.5 N/A
Vandyke 9 3.8
Argyrotype contains approx. 1.8-2.4x more AFC than the comparison. (And
2.7x more silver!)

Knowing Sam Wang's preference for using Argyrotype sensitizer diluted 1+1
with water (an information shared here by Christina Anderson before...), I
decided to dilute my sensitizer 2+1 (1 part water per 2 parts standard
strength stock sensitizer solution). Even diluted 2+1, the sensitizer would
still have 1.8x more silver than Vandyke, and my previous experience with
pop Pd was that there's only a marginal difference in dmax between iron
sensitizer strengths of 45% and (recommended) 60% - tested with matching
strength of Pd solutions. Therefore, I assumed it wouldn't hurt much in the
dmax department.

Indeed, now the diluted sensitizer works like a charm (Pd quality I would
say...) with this paper, and the resulting dmax leaves nothing to ask more!

This dilution trick also made me (finally) able to get absolutely neutral
to blue black and uniform results with gold-thiourea toner.

Therefore, if you have problems with Argyrotype, also try it by diluting
2+1 or 1+1, and see if that works and/or you like the results!

Regards,
Loris.

P.S. I still add 1d 10% Tween 20 per ml of sensitizer, FAEW has a very hard
surface therefore still needs some help. (OTOH, I actually didn't try it
w/o Tween, but I'm not going to fix it since it ain't broken!)