Re: pigment

All,
This question of cyanotype or prussian blue permanence has beem lingering in
literature for a while. Yet there are plenty of examples of perfetly good
looking cyanotypes from hundred years ago. I have been conducting my own
stability tests on the pigments that I am using. I t has been a couple of
months and we do get a lot of sun exposure in Texas. I will report which
pigmets do well in a few months (prussian blue from Daniel Smith is one of
the pigments tested).
Marek, Houston

>From: "Christina Z. Anderson" <zphoto@montana.net>
>Reply-To: alt-photo-process-l@sask.usask.ca
>To: alt-photo-process-l@sask.usask.ca
>Subject: Re: pigment
>Date: Tue, 22 Nov 2005 07:05:29 -0700
>
>I'm going to throw out something here you all can hash over.
>
>I don't use Prussian blue just because of some brands' purported fading in
>sunlight and recovering in the dark...Maimeri, Sennelier, Schmincke, Wand
>N...
>
>Page says she has not seen it recover.
>
>Whether this is fact or fallacy, thalo works so much better with more color
>saturation and clearer and smoother. But it seems to me that this chance
>would be akin to working with Alizarin nowadays when there are better,
>permanent reds.
>Chris
>
>----- Original Message ----- From: "Jack Fulton" <jefulton1@comcast.net>
>To: <alt-photo-process-l@sask.usask.ca>
>Sent: Monday, November 21, 2005 10:15 PM
>Subject: Re: pigment
>
>
>>Yes, the 'blue' of the cyanotype is Prussian Blue. The cool thing about
>>it is that it was the first true blue that was what one might call
>>inexpensive. It came around in the early 1700's, so Herschel knew all
>>about it when developing the cyanotype.
>>
>>One interesting anecdote for today's climate of terrorism is that Prussian
>>Blue and Potassium Iodide can be ingested to aid in the removal of
>>radioactive materials from the body. Both of these are chemicals of our
>>medium. The FDA approval of Prussion Blue is either coming up or was
>>recently approved. The U.S. is stockpiling capsules of it.
>>Jack Fulton
>>
>>
>>
>>On Nov 21, 2005, at 8:49 PM, Katharine Thayer wrote:
>>
>>>
>>>
>>>
>>>On Nov 21, 2005, at 6:55 PM, Dave Rose wrote:
>>>
>>>>Isn't Prussian Blue the same pigment/chemical that forms cyanotype
>>>>prints?
>>>
>>>Is it? I guess I've never heard or thought about what the final product
>>>is that forms a cyanotype print, but Prussian blue is hydrous ferric
>>>ferrocyanide or feriammonium ferrocyanide, is that what it is?
>>>
>>>To my eye, Prussian blue pigment has a greener cast to it than most
>>>cyanotypes I've seen, or than pthalo, which to my eye has probably the
>>>purest cyan hue for tricolor of the blue pigments available, followed by
>>>ultramarine. And to me it's a duller blue than either pthalo or
>>>ultramarine, and for those two reasons I didn't suggest it for tricolor.
>>>But I can't say for sure that it's not good for tricolor, because I've
>>>never tried it. I guess I was also influenced by someone who wrote the
>>>other day that he had tried Prussian for tricolor and it didn't work
>>>well at all.
>>>
>>>I feel another test
>>>kt
>>>
>>
>
>
Received on Tue Nov 22 09:42:18 2005