What is a Cyanotype?
A cyanotype is a kind of printing process that uses chemicals and sunlight to create the print. There are two processes, one involves potassium ferricyanide and ferric ammonium citrate. The new recipe uses potassium ferricyanide, ammonium dichromate, and ferric ammonium oxalate. Cyanotypes can be printed on any natural fiber (organic fabrics, canvas, cotton paper)
Cathy Corbishley Michel "Endurance - the ship in the ice”
History
• John Herschel created the process as a way to copy his notes in 1842.
• He used hyposulphite of soda as well as paper coated with iron salts to create the process.
• One of the first to put this process to use was Anna Atkins who published a book titled “British Algae: Cyanotype impressions.” It was a book of fern and leaf photogram cyanotypes.
• The process was also widely used for blueprints until computers were invented.
Traditional Cyanotype
ProcessSolutions A and B are not light sensitive separately, but when mixed together must be kept in low light areas.
D.H. Burnham & Co Carbide and Carbon Building General
The New “Mike Ware” Formula
This solution utilizes one mixture composed of three chemicals which must be stored in low light.
Pros and Cons of the Two Processes
Traditional• Easy to mix• Fewer chemicals required• Slightly lower cost for chemicals
• Long exposure time• Sometimes absorption is an issue• Values could wash out if
underexposed• Sometimes highlights stain• Algae could grow in part A
New• Exposure time is shorter• Reliable• Doesn’t get moldy• Absorbs more easily
• Takes longer to mix formula, more involved
• Heated water is required to dissolve chemicals
• More chemicals required
• Measuring cup • Two glass containers• Newspaper (to cover workspace) • Foam brushes • Spoons (for mixing)• Rubber gloves• Dust mask• Picture frame with glass (plexiglas requires a longer exposure)• Natural material (cotton, silk, organic paper)• A negative or leaves/branches to print • Ammonium ferric citrate • Potassium ferricyanide • Distilled water
Supplies
Traditional Step-by-Step
Part A:200 grams ferric ammonium citrate to 1000 ml distilled water
Part B:80 grams potassium ferricyanide to 1000 ml distilled water in separate container
* Store in opaque storage container and label* Wear gloves while mixing
Step-by-Step
• Allow paper to dry thoroughly under subdued light (safelight can be used)
• Hair dryer can be used on cool setting
or paper can be clipped on a line to dry
Mike Ware’s New Cyanotype Step-by-Step20 ml distilled water at 110 degrees to 10 grams potassium ferricyanide
Stir constantly until it completely dissolves
Mike Ware’s New Cyanotype Step-by-Step30 ml distilled water at 110 degrees to 30 grams ammonium iron oxalate
Stir constantly until it completely dissolves
Mike Ware’s New Cyanotype Step-by-Step
20 ml distilled water mixed into 5 grams ammonium dichromate, measure out.5 ml
Add .5 ml to ammonium oxalate and mix thoroughly
Mike Ware’s New Cyanotype Step-by-StepStir dichromate and oxalate mixture into ferricyanide mixture
Stir thoroughly
*Allow mixture to cool in a dark place (15 minutes to 1 hour)
Mike Ware’s New Cyanotype Step-by-StepSeparate green crystals through filtering
Scrape out any crystal residue at bottom of cup
Mike Ware’s New Cyanotype Step-by-StepAllow to drip, the volume extracted should be approximately 60 ml
Add distilled water to make final volume 100 ml
*Store in dark glass or plastic container and label
Place it face down upon the glass of a contact printing frame. Make sure it is glass, not plexiglas.
Place printing frame in direct sun or in a UV light box. Printing time varies with time of day, and solution used. A test strip will narrow down the exact time needed.
Expose in direct sunlight or UV light box. The traditional method requires 25-30 minutes exposure. The new cyanotype formula requires 6-8 minutes exposure.
Prepare a tray with water and a splash of hydrogen peroxide. The peroxide will oxidize the chemicals and make the print darker blue. (a process that would happen over time if not done now)
Resources• Photos:• http://www.f295.org/Pinholeforum/forum/Blah.pl?m-1263334552/
• http://www.architechgallery.com/arch_info/exhibit_docs/exhibitions_2006/chicago_loop.html
• http://www.christopherjames-studio.com/build/ALTcyanotype.html
• http://vimeo.com/7726616
• www.Flickr.com
• http://images.businessweek.com/ss/06/02/photofair/source/14.htm
• http://vwirtsch.blogspot.com/2010/10/camera-obscurapinhole-cyanotypes-and.html
• Information:• http://www.photography.com/articles/history/cyanotype/
• http://www.alternativephotography.com/wp/history/cyanotype-history-john-herschels-invention
• Ms. Kates