Men's fashion bared its legs on Sunday with short shorts grabbing the attention at Lanvin's spring 2014 show, as menswear grapples with how to juggle formal and informal.

Creative director Alber Elbaz and his menswear designer Lucas Ossendrijver teamed short shorts with tailored or casual jackets, blouses, and shirts worn with narrow neckties.

Seen by some as nothing more than underwear, short shorts -- requiring good legs and a degree of sartorial bravery -- were also much in evidence on the men's catwalks in Milan earlier in June.

"The three rules with shorts are that they must be tailored, not remotely creased and cut a few inches above the knee," Esquire magazine recently told its readers, without proffering any advice on the shorter variety.

Other looks at the Lanvin show, held in the elegant surroundings of Paris's National School of Fine Arts, included button-up shirts, trenches in cerise and midnight blue and soft, sleeveless blouses and tapered trousers.

Initial reaction was broadly positive with industry journal WWD praising "sumptuous, often feminine fabrics and a luscious palette". The website nowfashion.com called the collection "stimulating if slightly schizophrenic in its execution".

"Elegant in the extreme," added British GQ on Twitter, while UK heritage brand dAPPER England commented: "Shorts with blazers!! And socks."

Kris Van Assche's Saturday show for Dior Homme also explored the issue of formality and informality in menswear.

The shorts suit -- aimed at providing flexibility 'from beach to boardroom' -- dominated the Belgian designer's collection.

Van Assche went for longer, tailored shorts, summing the look up as "tuxedos meeting sportswear".

Later Sunday, five days of menswear shows wrap up with a keenly awaited second collection for Saint Laurent by French designer and skinny jeans aficionado Hedi Slimane.

Versace then picks up the baton late on Sunday with haute couture for autumn 2013/winter 2014.

Four days of couture shows begin in earnest on Monday with the collection of the season -- Christian Lacroix's come-back tribute to the late Italian designer Elsa Schiaparelli.

Lacroix, feted by fashion editors in the 1990s after he created the first couture house to open in a quarter century in 1987, lost his fashion house in December 2009 after it ran up millions of dollars in debts.

In his first collection in four years, Lacroix will present 18 reinterpretations of Schiaparelli designs for the relaunched fashion house.