On 4 October 2011, Thai Post issued a set of 4 stamps and an exclusive miniature sheet to commemorate International Letter Writing week. The stamps feature Cartoon characters of kids in various actions that show the travelling of letter.
International Letter Writing Week was established at the 14th Universal Postal Union (UPU) Congress held in Ottawa in 1957 with the aim of contributing to world peace by encouraging cultural exchanges among the people of the world through letter writing.
Letter Writing Week spans the one-week period that includes 9 October, the anniversary of the inauguration of the UPU. Nowadays the Week is a yearly event in Thailand and Japan. UPU focuses more on the International letter-writing competition for young people and World Post Day.