Australia is leading the way with the use of plus-size models: but for most retailers and designers, "plus size" is anything above a size eight, while the average woman is  size 14 to 16.

One women's fashion chain has broken from the pack. The general manager of Crossroads, Linda Whitehead, said the company increasingly represents "the real and everyday woman" in its advertising .

The company's decision to use plus-size models didn't only mean a token size 10. 

"In this industry, size six to eight models seem to be the norm. And for a while there, we were just conforming to the industry standard," she said. 

"We sort of had this moment of clarity where we realised, hang on for a second, the women we're using to represent our customer and brands aren't [doing that]," said Ms Whitehead.

"And even more alarming: are we actually making our customer feel bad about herself, about how she looks in our clothes?" 

When the company tested using two models sized 12 to 14 in different campaigns, the response from customers on Facebook was "overwhelming", she said.

"I'm never going to look like those already skinny ladies who have had every bump removed," said a customer called Jane, adding that she "actually looked" at the photo. "But this model lets me imagine the dress would look good on me."

Last week, Calvin Klein was accused of called a slim model "plus-size" in a new advertising campaign.  Social media saw his comment as the "moral equivalent of eating a baby orphan," according to Time magazine, which noted that Klein didn't even say these words.

Meanwhile, on Thursday, Vogue magazine published a photo gallery of women of all shapes and sizes called, "Give me a D! Give me an F!" Because Gorgeous Bras Come in All Shapes and Sizes" – with many expressing delight on social media.

Best. Decision. Ever: #Vogue embraces stretchmarks, cellulite, and stomach rolls in its latest #lingerie editorial. http://t.co/rkrl84Tgmq — The Gloss (@theglossdotcom) November 13, 2014

The public is "rightly outraged" over comments that suggest a plus size is somebody who wears a size 10 or 12, said Chelsea Bonner, the director of plus-size modelling agency Bella.

"In the modelling industry, anybody over size eight Australian is a plus size," she said.

Thanks partly to social media, attitudes were changing, said Ms Bonner, whose agency now represents 200 plus-size models including the new face of Pantene, Robyn Lawley.

Every day a new retailer, magazine or designer, which had "never booked a model over size 10, 12 and 14",  was doing so and getting fantastic responses, she said. Average-sized models were being increasingly mixed in with thinner models, in the same way that a blonde and a redhead might be used to represent a range of buyers.

Running Bare, which specialises in workout wear for women, has found it "extremely effective" to include larger and average sized women in its advertising, said marketing manager Julia Bills. Women sized 18 to 22 were "so grateful", she said.

Ms Bonner started Bella in 2002 in desperation after working as a creative agent booking "half-starved and grey" looking models for fashion magazines.

For Ms Bonner, one of the most exciting changes was the decision by Supre – a brand appealing to younger women – to use larger girls in its advertising.

"Teenagers are so affected by what they see, so if we catch them when they are young, and say it is OK to be that size and you can still be healthy, then we don't get them into that cycle of self-abuse."