The Wet-Plate Collodion process was invented in 1951 by Fedrick Scott Archer. Collodion and Silver were used on multiple surfaces, resulting in Ambrotypes, Tintypes, etc. Ambrotypes are collodion on thin glass places with a dark backing to make the appearance of a positive image. Further bleaching and sensitizing are used to make ambrotypes into negatives. 

These paper negatives were created when I attended a workshop, The Handmade Negative taught by Dan Estabrook and Meercedes Jelinek.

Blackwell, K., & Maddox, J. C. (C. Johnson, Ed.)“Calotypes,” Print Processes Represented in Prints and Photographs Division, Library of Congress, Washington, DC.