This postcard shows a collage made with 24 Mexican Commemorative stamps, issued from December 1, 1970 to December 31, 1971. The message printed in blue on the back is sending greetings from the local Post Office in the 20th SCT Home Fair and shows how to place the postal zone in the address.
The stamp on the back is a definitive stamp of the Puebla Cathedral that was used for many years. It has a special cancellation from the fair
This is a post for Sunday Stamps at Viridian's Postcard Blog