This set features sun-developed blue-tinted photos which are self-developed by the sun. They measure approximately 2 3/16" by 2 3/4". The backs are blank. The cards are unnumbered and checklisted below in alphabetical order. Holders in excellent condition are fairly rare and add a value of at least $25 to any individual clopay. It is believed that 100 subjects were issued for this set so any additions to this checklist are appreciated.