Speaking of toning cyanotypes
We cannot let a day go by w/out recognizing "The World Journal of Post-Factory Photography", which, in Issue #7
has an article on page 36-38 by Judy Seigel about toning cyanotypes. It has most of the info you will need.
Here are my two formulae, not used or tried now for a few years. However I still have my print, made on a good quality cotton torn from an old bed sheet that is black, faded just a bit, but still black.
for Cyanotype (1)
1 teaspoon tannic acid in one liter of water.
teaspoons of sodium carbonate in one liter of water.
Immerse print dry or presoaked, but not
just right out of wash water from being made, into solution A for about two
in clear water for about a minute.
in solution B for less than a minute and rinse again.
the print in solution A again and watch carefuly. Remove it BEFORE it gets to
the color you want.
for Cyanotype (2)
dry print in Ammonia solution ( 12.6 ml per liter)
bleached, place in Tannic Acid bath (23 gm per liter of water)