Salted paper print was an early negative/positive printing process developed by William Henry Fox Talbot in England in 1839. Many beautiful examples of this process were created in the 19th century and can be found in a variety of photograph collections.
Harvard’s Weissman Preservation Center (WPC) undertook Salt Print Initiative at Harvard, a university-wide project to preserve and enhance access to salt prints at Harvard. The project focused on photogenic drawings, paper negatives, and salted paper prints (positive prints created from paper or glass-plate negatives) found throughout Harvard’s libraries, archives, and museums. The Fine Arts Library holds many salted prints in our special collections.
You can learn more about Salt Print Initiative at Harvard on https://projects.iq.harvard.edu/saltprintsatharvard