"Indigo" is an unusual piece done in a medium of cyanotype. Artist is Scott Kitts.

Cyanotype is defined as a slow-reacting photographic printing formulation. It is a monochrome print or image made by placing objects on a pre-prepared light-sensitive surface. Cyanotypes are created without a camera, so the prints or images they create are correctly called photograms. The name ‘cyanotype’ is derived from the Ancient Greek words for ‘dark blue’ and ‘mark/impression/type.'