Former staff are being asked to share their memories to celebrate the after-dinner treat's 40th anniversary.
The Rowntree Mackintosh factory, which was considered technologically advanced, employed hundreds of people in West Yorkshire from the early 1970s until 2012.
Wakefield Council are planning to hold a display and community event at Castleford Museum later this year, and are hoping to use local recollections of factory life in the exhibition.
More than a billion After Eights were produced by the factory during the chocolate's heyday as a vital part of middle-class dinner parties.
Coun Les Shaw said:
“I am pleased that the story of one of the most famous mints, and the people who produced them will be recognised in this new exhibition.
“It is mind-boggling to think that over a billion After Eights were produced in our district and enjoyed by people from all over the UK. Many of us remember the adverts which celebrated After Eights as an essential part of a posh dinner party.
“So I’d like to encourage anyone with memories of their time at the factory, or with a story to tell, to get in touch with the museum staff.”
People are being asked to share their stories by emailing Steven Skelley at firstname.lastname@example.org or by writing to him at Wakefield Museums, Wakefield Council, PO Box 700, Wakefield One, Burton Street, WF1 2EB.