Designer collaborations don't come much better than Peter O'Brien's for Arnotts - all clean lines, simple shapes and impeccable attention to detail, with more than a touch of Paris, writes DEIRDRE MCQUILLAN

PETER O'BRIEN'S second collection for Arnotts, which made its debut last week, is a capsule winter wardrobe that is grown up, covered up and classy, its deliberately restrained colour palette very much in keeping with the designer's trademark style.

With a mix of strict tailoring and what the French call "flou", it's a contrast to his more flamboyant and colourful theatrical costumes, but no less effective. Whether designing for the stage or the street, obsessive attention to detail and fabric has always been a hallmark of O'Brien's work, a throwback to years working in the rarefied world of Paris haute couture.

It shows, for instance, in the good deep hem that is very couture and gives a nice body, he says, to a bell-shaped skirt in duchesse satin, an alternative to the pencil shape.

Proportions matter. "Two or three millimetres' difference in the length of a hem can utterly make something look like something from the ICA 1965 or bang up to date," he says. The skirt is worn in a very O'Brien way, with a tight little polo with tiny buttons like a French sailor's sweater.

"It's important that the collection stays contemporary and natural. I hate clothes that look hammered on the body and I've always loved a sweater with a posh skirt," he adds. "And the buttons work; I hate buttons that don't work."

Dresses have sleeves. One in navy chiffon and crepe de chine is based on an haute couture Rochas dress from the mid 1990s when he was creative director at the Paris house. Arnotts's Deirdre Devaney saw it in New York at the launch of O'Brien's Workbook, a hand-printed book of O'Brien's theatre and fashion drawings, and asked if he could make an affordable version. The result is a demure shirtdress with a smocked and ruched bodice, 24 covered buttons and no zips.

Shoppers can choose from three coats: one has a full skirt and neat collar; another is a two-tone black and camel standaway number with patch pockets; and the third is a high-waisted slightly Victorian style, very typical of his buttoned up silhouette. There are high-waisted, wide-leg trousers that suit the tall and snake-hipped or slinky skinnies in double crepe that look better on shorter figures, both teamed with either crisp, white poplin shirts (with collar stands) or softer blouses in ivory crepe de chine. A mannish jacket in black double crepe has a dark navy border with Chantilly lace in-between, another couture touch, designed to complement cropped trousers in the same fabric.

Ranges for the high street by top designers often result in disappointment. If standards drop, reputations falter. Some well-known names have produced shockingly bad collections, but there are notable exceptions, particularly Jil Sander for Uniqlo.

There will always be compromises in such collaborations and as O'Brien says "you start on the sixth floor but may end up on the second or third", but this Irish designer has shown that, even with tight commercial constraints, it is possible to provide a collection of good quality and design that looks more than it costs.