[alt-photo] Re: potassium phosphate

[David Ashcraft]

Eric, I did a little reading (http://www.bostick-sullivan.com/articles/zia_ware.html 
) and it appears to give just a neutral tone where the potassium  
phosphate was reported to give bluish tones (History & Practice of  
Platinum Printing by Nadeau).

Where you able to get cold tones using NH4?  According to the chart on  
the B&S site neutral is the best listed as far as cooler tones are  
concerned and that by controlling humidity.  I find it interesting how  
much humidity plays a part in these different processes.  Time to  
build a humidity chamber!?  Will it still be considered Alt if the  
humidity is controlled digitally? -:o)

David


On Jun 28, 2010, at 2:04 PM, Eric Neilsen wrote:

> You will get cooler prints, simply by changing the ion to NH4  
> instead of Na2 than using the cold tone developer. That may be a  
> bigger