Dressing smart no longer necessarily means looking sharp in Japan. More often than not it refers to the clothes' function, as scientifically developed fabrics gain popularity. Among the hi-tech offerings now on the market are odor- eliminating socks billed as "self-deodorizing," shirts made of 100 percent cotton guaranteed not to wrinkle, and wool suits that revert to their original shape after a hard day of business abuse. Then there is the water-resistant suit. While it won't win fashion points, the suit is shown in a recent television commercial deflecting a flying cup of coffee. The wearer, rather than being scalded and stained, is left with only a few harmless beads of liquid to be brushed off. A new technique to coat material with resin was credited. Sales of these "smart clothes" are aimed mainly at middle-aged Japanese businessmen - a group sometimes considered uniformly dull when it comes to apparel. In reality, Japan's "salarymen" sport an astonishing variety of dress while keeping within the limits of conventional business wear. A typical Tokyo businessman can wear a 200,000 yen ($2,000) Ginza-tailored suit of worsted wool one day and the next appear in one of last year's more famous price busting bargains - suits that sold for 1,900 yen ($19) each. The vast range of business suits on parade in any Tokyo subway car does not exclude the shiny, the ill-fitting or the unintentionally odd-colored. If it looks like a suit, it'll do. And if it also comes with a practical advantage in maintenance, it'll do even better. The new hi-tech clothes appeal to those who prefer a good idea to simply looking good. Leading the trend was a new non-iron dress shirt that appeared on the market in 1993 to instant popularity. "We're still selling a lot of the wrinkle- free shirts," said Akemi Kobayashi of the Tobu Department Store's Ikebukuro branch in Tokyo, "although not as many as when they first came out because many of our customers have them already. They've been very popular with salarymen, but the ones actually buying them are their wives. They like the fact that they don't have to iron the shirts or pay to have them dry-cleaned." The soft cotton-polyester blend shirts were a hit product with businessmen used to either polyester that didn't feel good or all-cotton that required care. One maker alone reported selling more than 1.5 million wrinkle-free shirts in 1993. The market has since expanded beyond the salaryHL men's white into shirts with more colors and stripes. Wrinkle-free polo shirts and slacks have become the most recent additions to the trend. Since some consumers still consider any form of polyester a fashion crime, wrinkle-free shirts of 100 percent cotton have been developed as well. They look and feel no different from regular cotton shirts, but can be washed, hung up to dry and worn without ironing. Brisk sales are attributed to the successful reputation of the blend shirts, as well as to a number of customers who insist on all-natural materials. Wrinkle-free cotton shirts sell at prices between 5,000 and 9,000 yen, only slightly higher than that for a standard cotton dress shirt. If the dry-cleaning fees are eliminated, they represent a bargain, a big factor in their popularity among middle-level salarymen in recessionary Japan. The weather helps as well. Each summer Tokyo turns into an urban sauna, but unlike in some Asian cities the dress code never relaxes from its required suits and ties. Oppressive heat, humidity and the rainy season in June and July made the appeal of water-resistant and wrinkle-free clothes obvious from the start. Another wrinkle-free item that went over well in summer, according to Ms. Kobayashi, was her store's "Package Suit" which folds inside-out to become its own carrying bag. The 448,000 ($480) polyester-blend design was aimed at the traveling salesman type who needs an extra suit on the road but doesn't want to bother with a separate carrying case. The Konaka chain of clothing stores offers a suit made of a blend material said to be 10 percent more elastic than that used in its regular suits. Thanks to the new fabric and an adjustable waist, a store spokesman was quoted, the wearer is free to lose or gain weight without having to bother with alterations. A bigger success has been "shape memory" suits with the ability to repel wrinkles and maintain original design features such as trouser pleats. When they first appeared last year, the suits were touted mainly as a functional suit at an affordable price. With the concept still attracting consumers in large numbers, the selection has expanded to include a greater variety of designs, more colors, and better quality, with some higher prices to match. The 220-store Aoki clothing chain started using an Italian designer for its new line of suits appealing to men who will pay a little extra for a high-tech suit that doesn't look like a gimmick. The chain's new Antonio Fusco line of wool suits uses "shape-memory" technology it developed with several fabric makers and the International Wool Secretariat. It is advertised as the world's first 100 percent wool shape-memory suit. "We asked businessmen just what they wanted in a suit," said Keita Nagemoto of Aoki, "and they told us: a 100 percent wool suit they could wear even if it's raining or they have to take crowded commuter trains. Aoki expects to sell 200,000 of the suits in their first year on the market. DAVID TRACEY is a journalist based in Japan.