I tried to post this as an article, but for some reason, i can't get it to submit. Perhaps a mod could put it there. I'll give you a dollar....
Cyanotype is one of the easiest, least expensive, and least hazardous of alt process methods. It is a great way to get your feet wet with alt process. The only downfall is being stuck with a prussian blue image. While some images are wonderful this way, many people wish they could have a different range of tones. That is entirely possible, and what follows is the method I use to tone cyanotypes:
You start by making a standard cyanotype contact print. I use the Photographers Formulary kit. There are other formulas available, but I have found the kit from PF to work well as any other with this method of toning.
A small amount of hydrogen peroxide added to the developing water will speed development.
I have found negatives of average to low contrast and density to work the best with this method. The bullet proof negative tailored to Pt/Pd isn't as well suited, and can tend to block up in the shadows.
I use a drawing paper called Rapidograph. It holds up well, and it's cheap, but you may prefer something with less texture.
Once the "blue print" is in hand, you will need the following:
Sodium Carbonate-(this is available cheaply at many markets as washing soda- I use "Arm & Hammer Super Washing Soda" (NOT baking soda!!! That's sodium bicarbonate)
Tanin-This is cheaply available at brewers supply and is used in winemaking. It works much faster than tea or coffee, and can be mixed to taste.
I mix all the solutions at the temperature of my tap water, about 60 degrees F.
Temperature isn't important as long as it is consistent. Alternate warm and cold solutions can cause the paper to reticulate ( crinkle up, and develop "cracks") Also, overly warm solutions seem to make the paper more fragile.
The toning is done with two baths.
The first bath is a bleach. I use about one tablespoon of sodium carbonate to a liter. It dissolves better if you mix it into the water. If you add water to it, it has a tendency to cake instead of go into solution.
The second bath is the toner. I use about one teaspoon of tannin to a liter.
When the baths are ready, slide the print into the bleach (sodium carbonate solution) bath and gently agitate. The highest values will bleach first. I bleach until the lowest values begin to turn black. You may also see some oranges, purples and tans emerge. This all happens in about thirty seconds to a minute. When it looks almost right I snatch the print and put it in the a wash to stop the action and purge the agent. Don't worry that the very highest values have gone, they will come back to a degree, but don't go to far, either. The amount of bleaching has the greatest effect on the tones of the final image. Less bleaching can sometimes develop split tones, which can be really cool with some prints.
After the print as washed, you transfer it to the tannin bath, and tone to taste. This process takes the most time. If find twenty minutes with some occasional agitation to suit my tastes. Wash ,dry, press and appreciate.
Don't bleach or tone more than one print at a time, as contact with other prints can cause splotching, especially in the toning bath.
Thats it. Really simple.