Potassium ferricyanide is the primary photosensitive chemical used in cyanotype printing. It reacts with ultraviolet light to form an insoluble blue pigment.

Ammonium dichromate is the other photosensitive chemical used in cyanotype printing. It reacts with ultraviolet light to form an insoluble brown pigment.

The sensitizing solution in cyanotype printing contains the photosensitive chemicals that react with ultraviolet light to form an image.

The fixing solution in cyanotype printing removes the unexposed photosensitive chemicals from the paper, making the image permanent.

Watercolor paper is typically used for cyanotype printing because it is strong and absorbent, and it can hold the sensitizing solution well.

Exposing the sensitized paper to ultraviolet light in cyanotype printing causes the photosensitive chemicals to react and form an image.

Washing the exposed paper in water after exposure in cyanotype printing removes the unexposed photosensitive chemicals from the paper, leaving only the image.

Toning the image in cyanotype printing changes the color of the image by reacting the image with a chemical solution.

The most common color of a cyanotype print is blue, which is the color of the insoluble blue pigment formed by the reaction of potassium ferricyanide and ultraviolet light.

The color of a cyanotype print can be affected by the type of paper used, the exposure time, the temperature of the sensitizing solution, and other factors.

Cyanotype printing is a simple and inexpensive process that produces unique and beautiful images. It is also environmentally friendly because it uses non-toxic chemicals.

Cyanotype printing is a slow process and it is not as versatile as other printing processes. It can also be difficult to control the color of the image.

Cyanotype printing is used for a variety of applications, including fine art prints, photographic prints, blueprinting, and textile printing.

Notable artists who have used cyanotype printing include Anna Atkins, Man Ray, and Laszlo Moholy-Nagy.

Cyanotype printing is experiencing a resurgence in popularity due to its unique aesthetic and its environmentally friendly nature.