[alt-photo] Re: The Illusive Black Cyanotype - Any Insight?

[Gordon J. Holtslander]

Have you tried this:

To convert Cyano to black tones:
Place print in solution of 3 drops Nitric Acid added to 1 litre water 
for two minutes transfer to bath of 14g Sodium Carbonate + 160cc water - 
leave till image disappears and then reappears with an orange tone 
transfer print to third solution of 14g Gallic Acid + 160cc water - 
black tones will appear wash 30 min.

perhaps the ferrogallic process would work;
(from Photographic Facts and Formulas 1940)

ferric chloride		50g
ferric suplphate (basic)	25g
tartaric acid			45g
water				500 ml

Dissolve and add

gelatin				25g
water				250cc

soak gelatin for 30 minutes and dissolve

Development details are not given though

Gord

On 9/19/2011 9:14 PM, Francesco Fragomeni wrote:
> I received a coffee toning recipe a few minutes ago that I haven't tried
> before. Examples look pleasing. I'll be trying this soon. Anyone have
> success with this?
>
> -Francesco
>
> On Mon, Sep 19, 2011 at 7:32 PM, Francesco Fragomeni
> <fdfragomeni at gmail.com>wrote:
>
>> Hi all,
>>
>> I've been working for some time to achieve a black cyanotype but to no
>> avail. I mean true black and grays, not the purples, eggplants, and other
>> hues that can be achieved rather easily. I am 100% sure that it is possible
>> because I have seen examples in private collections. I have also seen a few
>> rare examples (unsubstantiated) on the web but I've been unable to initiate
>> conversations with anyone who has made one successfully. I've tried most of
>> the toning recipes and none of these achieve anything close to what I'm
>> looking for plus they have a tendency to stain the paper base. Tonight I
>> tried the nitric acid (nasty stuff so be careful)/ sodium carbonate/ gallic
>> acid recipe which is purportedly capable of rendering a black cyanotype.
>> This recipe produced more of a dark grayish purple in the shadows and a much
>> more obvious purple cast to the highlights. Now this may be worth
>> experimenting with again because my tests were based on re-soaking already
>> dry prints rather then making fresh ones which could possibly make a
>> difference (I couldn't make new prints because I'm waiting on a printing
>> frame to arrive to replace my unusable one). Can anyone here offer any
>> insight into how to achieve the illusive black cyanotype?? It would be so
>> unbelievably appreciated. Thank you!
>>
>> -Francesco Fragomeni
>>
> _______________________________________________
> Alt-photo-process-list | http://altphotolist.org/listinfo
>


-- 
Gordon J. Holtslander
gjh at shaw.ca