The listing, Vintage Collotype POSTCARDS Waterbury Naugatuck Bristol CONNECTICUT 16 of Them has ended.
Up for bid is a lot of 16 Connecticut Collotype postcards.
Collotype is a gelatin-based photographic printing process invented in 1855 to print images in a wide variety of tones without the need for halftone screens. The majority of collotypes were produced between the 1870s and 1920s.
I'm not sure when these were produced, as they are listed as "Published by the Collotype Company, Elizabeth, N.J. and N.Y." I have not found much mention or information of this company.
5 are of Waterbury, 1 of Bristol, and the rest of Naugatuck. 6 have been posted, and those posting dates are all in the 1940s, but the cards themselves may have been produced earlier. I enlarged a couple places with cars (last two scans), so that may give you an idea of the year. I would say these are in excellent condition for their age.
I have shown the fronts of all, the backs of one of the posted ones (and the posted ones are all pretty similar), and one of the unposted backs.
Smoke-free items.