Updated: new stamps in and we are starting to see a time line on a couple of agencies via their stamps: …have a view on our PressPhotoHistory
On our Press Photo History site we are collecting photo agency stamps …. uploaded a few new finds over the last few days Here
Photo agency stamps were the email and website details of the pre digital age, stamped on the reverse of a photographic print to identify the copyright holder if the image was chosen for publication.
For the Press Photo History Project the information on these stamps identify the current address of an agency at time of printing, which helps with our Photo Agency directory tracing the life of a particular agency or Newspaper photo department, like this one below from The Times: