Re: blue on blue
Sal Mancini (sal@www.napc.com)
Tue, 11 Feb 1997 13:11:42 -0500
Judy Seigel wrote:
>
>
> Plain Old Cyanotype
>
> A. 20 g ferric ammonium citrate in 100 cc distilled water
> B. 8 g potassium ferricyanide in 100 cc distilled water
>
Judy,
I used a slightly modified version of the formula:
A. 25 g ferric ammonium citrate in 100 cc distilled water
B. 8 g potassium ferricyanide in 100 cc distilled water
The amount of feamcit would vary depending on paper base and contrast
range. The more FeAmCit, the less contrast. Too much and you lose
DMAX. The 25 g version has a contrast range that accomadates a longer
scale neg such as one used for platinum. I recently Made some
cyanotypes using the premixed sensitizer from B&S. I made a print
using a negative that printed well with the above mentioned formula.
The Ware formula seemed to give a better dmax wiht one coating than
25g does wiht one coating. I had always doublecoated to get a good
dmax with hte old formula anyway. The doublecoated old formula
produced a much higher dmax than the Ware formula
singlecoated.However, I did not test the Ware formula wiht two
coatings. I suspect that the dmax will be just as good if not slightly
better.
Sal Mancini