While that is a boost for the female ego ¨C what woman would not want to drop a dress size or two? ¨C it is causing chaos in changing rooms.

Some fashion retailers and designers are being accused of making their clothes in "more generous" sizes as a marketing ploy to make women believe they are smaller than they really are and lift sales.

In Australia, where the textile industry is grappling with the problem, it even has a name ¨C "vanity sizing".

Gone are the days when women are a classic size 10 or 12. Most women's wardrobes have clothes spanning two or three sizes, whereas petite women are forced to shop in children's clothing stores.

In a confused marketplace, it is no longer unusual for a size 10 to be as small as an 8 or as big as a 12.

The problem is spilling over to New Zealand, both in imported Australian labels and in local designers admitting their sizings are more generous than in the past.

Fashion Industry New Zealand chief executive Mapihi Opai believes consumer vanity is partly driving the trend towards super-sized clothes.

"Women love to put on a garment and come out a size smaller," she said. "You get that discrepancy in sizing across all clothing in New Zealand. Probably the only area you don't get it is in babywear and childrenswear."

Blonde Red designer Sharyn Barker is constantly asked what the sizing is like in her High Street store.

"Our reply is always that it varies so much, it is best to try it on," she said. "I think New Zealand designers are better than the Australians, but then you do get some of the more well-known labels that definitely add generosity to their sizes."

New Zealand used to have its own national standard for women's clothing sizes but that was replaced by a 1997 Australian version, also considered past its use-by date.

Whether Kiwi women, with their unique blend of ethnicity, have the same dimensions as their Australian counterparts is debatable.

So The Press did an experiment of its own and found glaring discrepancies among popular labels in central Christchurch.

It enlisted the help of Sam Jacob, a professional shopper from retail spies Customer Care and a svelte size 10.

Jacob was just able to squeeze into a size 10 trouser in Principals, but swam in a size 10 trouser from Cue, both in the City Mall.

In fact, out of five shops visited, Jacob fitted size 10 pants in just one of them.

In three shops ¨C Australian chains Cue and Country Road, plus Stax ¨C she snugly fitted a size 8 trouser around the waist, although most were too long in the leg. In Max, she fitted neither size 8 nor 10. "I need a size 9," Jacob said.

Further proof of this blurring of sizes was found in Jacob's own clothes that she wore on the shopping mission ¨C size 10 trousers and size 12 long-sleeved T-shirt, worn under a size 8 top.

"I would have a huge mix in my wardrobe of sizes 8, 10 and 12," she said. "It goes to show we are all individuals."

Veteran Christchurch designer Barbara Lee said clothes had gradually got bigger over the years she had been in the business.

"It's pretty seriously confusing," she said. "Another reason why clothes are sliding up the scale is that I don't want to be any bigger than a size 12."

But are other women getting bigger? "We are all going to the gym and we're all toned and we've got great butts and great boobs and slim waists, haven't we? No! Well, we're healthy."

If a client had a problem with the size on the label, Lee joked that she would gladly change it to whatever they liked "for a small fee".

Opai said women could avoid the size trap by finding design houses which had sizes and cuts that fitted.

"Designers come to know exactly who their market is, where they sit within a socio-economic group and also where their build is," she said. "Within labels there is standardisation across all of their garments and from season to season."

Apparel Magazine editor Paola Ghirelli said more research was needed to establish how New Zealand women's figures compared with Australians.

"Then they can come to some sort of conclusion as to whether the sizing needs to be changed or whether the sizing is totally inappropriate," Ghirelli said.

An Australian group calling itself the Sizing Consortium of Australia Landmark Evaluation ¨C which includes Standards Australia and fashion and textile representatives ¨C plans an extensive survey on size in Australia.

It wants to measure 5000 to 10,000 people using 3D imaging technology, but is yet to find the $3.6 million to $6m needed for the project.

An Otago University group keen to do a similar project in New Zealand has also failed to attract funding.