Cyanotype is a photographic technique used since the 19th century. A mixture of photo-sensitive chemicals is painted onto paper or fabric, which is then pressed into a frame and exposed to the sun. You can use objects, such as plants or feathers to create patterns or use a digital negative of a drawing or photograph to make a photo-real image. The result is always blue.
“A photograph is a picture painted by the sun without instruction in art.” — Ambrose Bierce