9 1/2″ x 7 1/2″ Collotype photograph ca. 1900-1910 on original 11 1/2″ x 9 3/8″ mat. This photograph is in excellent condition. The beautiful tones allow for great detail.
Charles H. Carpenter was an American photographer known for his photographic work during the 1904 Louisiana Purchase Exposition in which he produced 2,000 negatives. His photographs of Native American life are celebrated, having taken over 900 photographs of the Hopi tribe in 1900. He was also the Field Museum’s photographer from 1899-1947.
The Collotype is a dichromate-based photographic process invented 1856 and used for large volume mechanical printing before the existence of cheaper offset lithography. In the process, a plate (aluminum, glass, cellophane, etc.) is coated with a light-sensitive gelatin solution and exposed to light through a photographic negative. The gelatin is hardened in exposed areas and is then soaked in glycerin, which is absorbed most in the non-hardened areas. When exposed to high humidity, these areas absorb moisture and repel the greasy ink. The hardened areas accept the ink, and the plate can be used to print a few thousand copies of the positive image. It can be identified under small magnification by the presence of image reticulation, a product of the finely cracked gelatin plate used to print the image.