After his show today, Giambattista Valli admitted he's finally got his two worlds sorted: Prêt-à-porter is inspired by his personal experiences; haute couture is his fantasy. Where once they were borderline, now there is no dialogue between the two. So his latest collection flowed on organically from Spring, particularly in the casual interplay of masculine and feminine elements.

It may have been Valli's most accomplished ready-to-wear offering to date. It was certainly his easiest. It opened with a parka and closed with a car coat, both accompanying casual pieces in pristine white. Valli felt the greatest testament to his success was that he could imagine his favorite customers Lee Radziwill and Bianca Brandolini d'Adda, separated by half a century, both looking good in either of those outfits.

He could also picture any of the women who lined his front row throwing on her husband's or boyfriend's old sweater, suitably customized by moths, or wrapping up in his jacket or coat. Valli gave them all those options. His coup de grâce was the flat shoe—furry loafers or his version of Vans—which dressed down the formality of a brocaded suit or a classically draped cocktail dress. The result was a night-for-day glamour that justified, for once, the overused adjective "effortless."

Then Valli went in the opposite direction: dressing up casual sportswear looks like a tracksuit in a Swarovski-ed eau de nil, or the zipped blouson and matching pants under a coat of red astrakhan. Zips stood out all over the place because they were paired with some subtly impressive fabric treatments: glazing, lacquering, brocading. It was, Valli said, his way of conveying the alchemy that takes place in an urban environment, where clothes acquire an appealing patina from their environment (moths chewing their way through knitwear being perhaps the most aggressive example).