M&S archive images chart the history of the bra
Marks and Spencer has raided its archives to chart the history of bras.
Garments from the 1920s and decades-old adverts were among the items pulled from the retailer's 70,000-strong collection of historical objects.
The firm, which claims to have introduced cup sizes to UK consumers 50 years ago, hosted a talk about the finds in Leeds, where M&S was founded.
Archivist Katie Cameron said the City Museum event offered "a glimpse" into its past innovations.
According to the company's website, it launched small, medium and large cups in 1951, which "didn't lend very much scope for different sizes of women," Ms Cameron said.
It was another 18 years before the company launched A-DD sizes.
Ms Cameron said the talk would highlight decades of changing styles and design innovation.
"There's been all sorts of change," she said.
Sisters and seasoned M&S shoppers Janet Roche, 69, and Kay Susan Ballantyne, 71, from Hull, recalled the first time they were fitted for a bra.
Mrs Roche said: "Bras back then in them days were more or less the same, where as now you can choose different sizes and styles such as strapless and things."
"You didn't have things like that a long time ago."
"But whether or not it fitted properly I don't think you thought about that."
"You didn't know your cup size back then," added Mrs Ballantyne.
But despite boasts of innovation, there are calls for retailers to do more in the search for the perfect fit.
Prof Joanna Wakefield-Scurr, who set up a bra-testing research centre at Portsmouth University, said the sizing system had changed "substantially" over the years with exact measurements for all cup sizes differing at nearly all retail outlets.
"There's no universally accepted bra sizing fitting and grading system. Sizes change from shop to shop," she said.
"There needs to be consistency and this is a real challenge for the bra industry."
Nicola Johnson, a course leader at London College of Fashion, said the industry was "seeing a shift in women's sizing" and echoed Prof Wakefield-Scurr's calls for "universal measurements".
"Some of the brands are simplifying it even more for themselves but not for the consumer," she said.
"If you're wearing a poorly fitted bra it can have a big impact on your health and can lead to breast pain and damage to breast tissue."
More information can be found about the M&S archive here.