Re: Prussion Blue - Fresson Paper Analysis


Liam Lawless (lawless@vignette.freeserve.co.uk)
Fri, 29 Jan 1999 19:23:59 +0000


Hi Art,

Make your own. All you need is a couple of teaspoons each of pot.
ferricyanide, ammonium iron (II) sulphate, and some water. Iron (II)
[ferrous] sulphate should also work, but I couldn't find mine when I tried
it.

Add the chemicals to about a pint of water and a deep blue liquid will
result; on standing for an hour or two the Prussian blue precipitate will
settle. Wash if necessary by pouring off as much water as possible, and
replacing with distilled. Collect the precipitate by filtering.

According to my book of artists' materials, the Prussian blue used in
pigments is ferric ammonium ferricyanide, C6FeN6.H4N, "precipitated by
reacting a ferrocyanide with a sulphate and then a (bi)chromate.
Alterations in processing and after-treatments result in many specialty
grades."

Whether what I made is ferriferrocyanide or ferric amm. ferrocyanide I don't
know. But reacting ferrous sulphate with pot. ferri. should produce the
photographic variety,

Liam

-Original Message-----
From: Art Chakalis <achakali@freenet.columbus.oh.us>
To: Alt-Photo-Process-L List <alt-photo-process-l@sask.usask.ca>
Date: 27 January 1999 00:34
Subject: Prussion Blue - Fresson Paper Analysis

>
>I need a small sample of the pure powdered pigment Prussian Blue (which is
>ferric ferrocyanide).
>
>Does anyone out there own some of this? A half of a gram is all that I
>need for a comparative analysis.
>
>Sincerely, Art
>
>
>
>
>
>Art Chakalis
>Columbus, Ohio, USA
>
>
>



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