Cover of a letter of 18 October 1964 addressed to Prof. Witold Romer.

It was sent from NIKFI of Moscow (Soviet Union) i.e. Cinema and Photo Research Institute [Научно-исследовательский кинофотоинститут]. NIKFI was established in 1929 for research and development in all aspects of motion pictures technology.
The cover bears stamped NIKFI frankmark.