Donald J Mitchell was born in Ottawa, Canada, on 23 October 1930. He went to the Glebe Collegiate and the Ottawa technical High School.
In 1949/1950 Mitchell joined the Canadian Bank Note Company, where he became the apprentice of the letter engraver John F Mash. Mitchell himself also became a letter engraver, working on some 44 Canadian stamps. He retired in 1996.
You will find Donald J Mitchell's database HERE.