Mr Forster was born in Leeds on November 26, 1915, and left school at the age of 14. His first job, as ten shillings a week in October 1930, was as an office boy at the Leeds printing company of Chorley & Pickersgill.
Printing and journalism were perhaps in his blood: his grandfather, Edward Forster, and uncle, Stanley Forster, were both managing directors of Knight & Forster Ltd, a long-established printing company which had premises in Water Lane, Leeds, until the late 1990s.
Ken Forster’s career as a sales representative at Terry’s began in 1939, and was interrupted by six years during the Second World War with the Royal Army Service Corps in North Africa, Italy and Greece.
He began collecting postmarks in 1931. The Postmark on a Letter, the first of his four books on postal history, was published in 1952.
He wrote a series entitled Yorkshire Postmarks, which ran in the Yorkshire Evening Post for six years from 1965.
His column Postmarks, Places and People featured for 36 years until 2003 in the monthly Stamp Magazine and he was a frequent contributor to the Yorkshire Post and many other regional newspapers and trade magazines.
He became a regular winner of all types of competitions, especially those requiring entrants to write an eye-catching slogan in a dozen words or so.
Mr Forster moved in 1934 to Huby (between Leeds and Harrogate) where he met Heather Williams, who worked as a secretary for the Blood Transfusion Service at Leeds General Infirmary. Their wedding was at the Methodist Chapel in Huby in August 1940, and they were married for 62 years.
The family moved from Leeds to Scarborough in 1954; Mr Forster was a member of Scarborough Writers’ Circle from then until his death. Mr Forster, whose wife died in November 2002, is survived by his son, John, his daughter, Clare, three grandchildren and five great grandchildren.