Re: Re: cyanotype

Hi Loris,

You need a little potassium ferricyanide to trigger the ferric ammonium citrate dvelopment. The original
formula is too much. It appears that one part B to two parts A is about right in achieving increased
sensitivity with no ill effects. More than that will only decrease speed (adding self masking) to an
already slow process, plus dumping extra potassium ferricyanide down the drain.

Sam
>
> From: Loris Medici <loris_medici@yahoo.com>
> Date: 2004/05/29 Sat AM 05:10:02 EDT
> To: alt-photo-process-l@sask.usask.ca
> Subject: Re: cyanotype
>
>
> Hi Sam,
>
> ----- Original Message -----
> From: "Sam Wang" <stwang1@bellsouth.net>
> To: <alt-photo-process-l@sask.usask.ca>
> Sent: Saturday, May 29, 2004 4:20 AM
> Subject: Re: cyanotype
>
>
> > Hi Gord,
> >
> > Just potassium ferricyanide alone may not be much good for making prints,
> but ferric ammonium
> > ...
> > But why would one want to do it with just one ingredient?
>
> A speculation:
> Could it be to prevent "self-masking"? I understand that cyanotype is kind
> of self-masking process - because it prints out with considerable amount of
> density - and maybe if one expose with just Ferric Ammonium Citrate there
> will be less density before Potassium Ferricyanide developing which means
> less self-masking?
>
> Regards,
> Loris.
>
>
>
Received on Sat May 29 07:54:05 2004