Who saw the The No 1 Ladies' Detective Agency, set in Botswana and shown by the BBC on Easter Sunday? It is now being made into a series, so there will be more opportunities yet to see the superb fashions in it - most notably the wonderful print dresses worn by Jill Scott, who plays the part of Precious Ramotswe. Jill is not a size zero, nor would you ever want to be again if you see her.

The dresses were designed and made - all but one of them - by the costume designer to the film, Jo Katsaras. Botswana's traditional fabric is called shweshwe or "German print" (the printing process originated in Germany). It's mostly browns, blues and reds, and I really wish someone would make me a dress in it.

From Melbourne, where she's currently working, Katsaras tells me: "The prints themselves are quite distinct in African culture and are often repeat patterns, which makes it quite tricky to cut sometimes. The designs were simple in shape and I chose to let the prints and embroideries be the feature. In fact, they had a lot of detail in that regard." They are truly magnificent.

But it raises the question rather: why don't we get dresses like that over here for bigger women? Although if we did, I wonder if they would wear them with quite the same sense of ownership as Jill Scott does.

"Jill was a dream to work with, and she carried the designs beautifully," confirms Katsaras. "I love the way Africans have a quirky sense of style, using textures and different prints and styles together. You'll see a woman wearing three different florals with a stripe, and then she'll have a checked scarf or accessory. It's uniquely African and they carry it so well."

I can't help thinking that if the high-street CEOs wanted to be really clever, they would fly Katsaras over to help them inject a much-needed bit of glamour and sexiness into their "plus size" ranges, instead of paying tiny celebrities ludicrous sums to design clothes for equally tiny people. The clothes in The No 1 Ladies' Detective Agency show that it really can be done. In fact, I'm wondering why more high-street stores don't take advice from film costume designers. After all, actors are far more likely to be human-shaped, so the costumiers are used to working with curves, bumps and maybe even the odd lump.

I often find that I want the clothes shown in a film. This is because - perhaps it's my age? - I find clothes more covetable when I see them on screen, rather than lying flat, in a magazine. As costume designers clearly know what they're doing, perhaps it's time to bring their talent out from behind the screen and on to the shopping rails. Until then, I shall spend the best part of the summer trying to locate the perfect print dress for myself. No doubt I'll find it just as we slide into autumn.