Re: pigment

Actually, I covered this when I was discussing Prussian blue for
monochrome a couple of weeks ago; although I am used to repeating
things over and over, at least I hope to get to wait a couple of months
before I have to say something again. Anyway, I said then that
Prussian (PB27) is one of the very few pigments where permanence varies
greatly according to brand. M. Graham, Daniel Smith, Winsor &
Newton's paint named "prussian blue" and DaVinci are excellent for
permanence, according to McEvoy's tests. Lukas, Maimaeri Blu and
Rembrandt are marginal. The rest, including another Winsor & Newton
PB27 paint marketed as "antwerp blue" are unacceptable with regard to
permanence. I certainly wouldn't avoid the color just because you have
to be a little selective as to brand; it's a very interesting color.
Katharine

On Nov 22, 2005, at 6:05 AM, Christina Z. Anderson wrote:

> 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 10:16:29 2005