I recently ran across the beautiful photochrome print from around 1900 of the Durango-Silverton Railway above the Animas River gorge in southwestern Colorado. It immediately reminded me of a trip that I took on the same railway line a few years ago. These days the route carries tourists through the wild country of the gorgeous San Juan Mountains, but between 1882 and the 1920 the railway served mining companies in the region. The view below is a contemporary shot of the same mountian gorge and the historic steam train that still follows the route.
I’ve featured photochrome prints from the Library of Congress a number of times over the years, as well as images from the Detroit Photograph Company which produced popular photochrome postcards between 1890 and 1924.
A litho stone was coated with a thin layer of purified bitumen dissolved in benzene. A reversed half-tone negative was then pressed against this light-sensitive coating and an exposure in daylight made (taking from 10-30 minutes in summer, to several hours in winter). The bitumen hardened and became resistant to normal solvents in proportion to the light. The coating was then washed in turpentine solutions, removing the unhardened bitumen. It was then retouched in the tonal scale of the chosen color to strengthen or soften the tones as required. Each tint needed a separate stone bearing the appropriate retouched image, and prints were usually produced by at least six, and more commonly from 10 to 15 tint stones.
Background from NYPL:
The Detroit Photographic Company originated in 1898 to promote a new color printing process in the United States and to capitalize on the public’s interest in sending inexpensive pictorial greetings. In 1905 the firm became the Detroit Publishing Company, continuing to use the trade name “Phostint” for its patented color reproduction process. Western landscape photographer William Henry Jackson was long associated with the firm, bringing his and other photographers’ negatives to the image stock published by the company. Photographers’ names are not associated with individual postcard images, although art reproductions and illustration series are credited. Diminishing sales and rising competition from rival firms sent the Detroit Publishing Company into receivership in 1924, and its assets were finally liquidated in 1932.