I think it's important to keep the difference between Collodion Dry-Plates which we have been discussing and the much different Gelatin Dry-plates that came along in the 1880's, and became the basis of film we still use today. They are not the same thing. The information on deals with the Gelatin Dry-plates.

Collodion Dry-plates were developed from the original Collodion wet plates and ambrotypes and tin-types of the 1850's - early 1880's. They are entirely different chemistry and process and much more rare today.