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| Cyanotype Portfolio Technical Matters |
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Thanks to Sir John Herscel in 1842 for discovering that ferric (iron) salts could be reduced to a ferrous state by light and when combined with other salts they created a blue and white image. Using Herscel's discovery one can apply the chemistry to a variety of papers, fabrics and canvas for a unique blue image. A negative, the size of the desired finished image is needed. The paper surface is coated with the chemical mixture and then left to dry. The negative is snugly pressed together, with emulsion against the papers chemistry emulsion, and both are placed into a contact frame with the negative against the glass. Pressure is needed to maintain accurate alignment of negative and paper. A backboard in the rear of the contact frame is used to complete the necessary pressure. The contact frame can be placed directly in the sun or under a UV light source. When the print exposure is finished a plain water wash will develop the ensuing beautiful blue image. Patience is needed during the exposure. Exposure time varies due to the sun's available UV light. It is not uncommon to have 20 to 30 minute exposures. Early and late day exposures could last up to 45 minutes. Other than being able to enjoy the outdoors during these extended exposures, there are other reasons for my interest in the Cyanotype method. The foremost is that the Cyanotype image is highly archival. Another, is that "blue" is my favorite color. I use a verity of negative formats to create cyanotype images. On occasion I use an old Brownie box camera, in which the viewing mirror is very poor, composition of those images is often just a guess.. Many of my cyanotype's are contact printed using a 4 X 5 negative. I have also used 8 X 10 and even a Holga plastic camera. NOTE: Images are of low resolution for internet viewing purposes. Please consider that tonal values are approximate. Sizes of original images are not stated but vary from Images are available for purchase please contact me using the link, "Contact"
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