Calvin Klein is a master at designing clothes so pure and clean that they look almost undesigned. Karl Lagerfeld is an inventor of ingenious new cuts and color combinations. The two showed their collections back-to-back here this week as part of the 10-day marathon of designer presentations for next fall.

The differences are apparent in their big coats, a successful theme in both collections. One of Klein's best is a long, full-skirted wrap coat, as simple and as luxurious as can be. Lagerfeld also does a full-skirted, very long coat, adding a contrasting belt and three decorative buttons.

There is nothing decorative about Klein's clutch coats -- what you notice is the softened shoulder, the dolman sleeve, the unexpected knee length and the rich camel's hair or leather. Lagerfeld's best clutch coats, by contrast, are in striped wool with an uneven panel at the front.

Klein's fabrics are among the richest he has ever used -- alpaca, cashmere, the most expensive wools. Lagerfeld opened his collection with denim, cutting it into terrific long, skinny trumpet skirts, complicated shirt dresses and even a strapless dress for evening -- to be worn with an iridescent fake-fur stole, of course.

"This is really the top of the line, some of the most expensive fabrics and the best quality of workmanship I've ever used," Klein said as he received praise and kisses from Bianca Jagger, Fran Lebowitz, Iris Love, Catherine Oxenberg and Jerry Zipkin, who, along with top store executives and fashion press, attended the first of Klein's two presentations in his showroom yesterday.

"These clothes should be investment clothes," he said. Indeed, the prices will run at least 25 percent higher than last year. "As expensive as everything is today, clothes included, the point is that clothes should not feel dated in a year. One should be able to wear them for a very long time."

While using a lot of camel and gray and stone, Klein achieves tonal differences that work handsomely. He also showed more color than he has in a long while, particularly for day -- as in celadon, pink or avocado sweater sets, worn with long flared skirts or wide flannel pants.

Sometimes his subtle addition of color appeared only in the gloves, his favorite accessory throughout the collection. Daytime gloves are short, but some gloves for evening extend all the way up the arm. "For example, a long black suede glove with a cocktail dress changes the whole look," he said.

Klein and Lagerfeld seem to agree on a preference for long, lean lines, but both offer alternatives. While most of Klein's skirts for day fall below the calf, some are short, as in two nifty merino knit suits with long, narrow double-breasted jackets and slim skirts in navy or saffron.

Klein is partial to a shorter look for evening, and showed some of the best cocktail dresses around. The sparest of all was a black silk strapless that seemed painted on the body of the model Dalma. Others combined charcoal or black wool and satin.

Klein said the black wool and satin short halter dress worn by Anna Bayle was the hardest for him to make -- how to wrap the black satin ribbon, just where to place the bow? "It is complicated to make it look simple," he said, adding with a shrug, "difficult to design and simple to wear, which I guess is what this is all about."

Just as he offers daytime alternatives, Klein also offers options for evening. Among the most surprising, and refreshing, are the very full, long Tasmanian black wool skirts worn with simple black cashmere sweaters. "I'd even love to wear that," his college-age daughter, Marci, whispered to a friend.

She wasn't alone. Klein got a standing ovation and shouts of "Bravo!" -- the first real cheers so far in the New York shows.