To attract more orders, makers are releasing models with special features. China's Langsha Knitting Co. Ltd is offering functional socks that are anti-bacterial, moisture- and odor-resistant, far-infrared emitting and flame-retardant. The use of high-tech materials such as ultrafine nanofibers and Coolmax pushes up the price of these models.

The FOB prices of Langsha's value-added socks are as much as $5 per dozen. The company hopes the higher prices charged for advanced models will increase overall profitability by 20 percent. While pure cotton models account for 50 percent of Langsha's socks output, the company also offers cotton or linen designs blended with nylon, polyester and spandex.

Model L4010 from China's Langsha Knitting Co. Ltd is odor-resistant. The toe sock is made of 92.1 percent cotton, 4.9 percent nylon and 3 percent spandex. Price is $2.

Shenzhen Huaziyi Enterprises Co. Ltd uses functional fibers such as DuPont's Lycra and Tactel and Filix-brand corespun elastic yarn from France in its high-end models. Prices are $2 to $5 per dozen. Among its new releases are cotton blend models with an anti-bacterial feature. Shenzhen Huaziyi produces socks from cotton, nylon, polyester and spandex.

Among its lines are midrange and high-end nylon socks for women. The company recently started producing socks in cooperation with Japan's Atsugi Co. Shenzhen Honesty Nano-Tech Co. Ltd, another China maker interviewed for this report, now specializes in functional socks. The company shifted its production focus to value-added designs a few years ago when competition grew intense in the sector for low-priced basic models.

Its functional models include anti-bacterial, massage and breathable socks. Each of these models involves a different weaving construction. The anti-bacterial socks, for example, require only post-processing treatment using nanotechnology.

The breathable socks are made from fiber that Shenzhen Honesty manufactures in-house. With a structure similar to that of an alfalfa leaf, the four-core fiber allows sweat to evaporate faster than cotton fiber does, giving the socks a cooling effect.

In India, SNQS International Socks offers sports models with a moisture-absorbing feature. This was achieved by incorporating a terry lining not just at the heels and toes but on the entire interior surface of the socks. By absorbing perspiration, the sanitized socks also fight bacteria.

Bonjour International has developed socks coated with certain chemicals that resist the formation of bacteria, making them odor-resistant. The company also offers models with an anti-pilling feature. The finished socks are chemical- and heat-treated to ensure that they will not pill.

Functional models are priced about 20 percent higher than ordinary socks.

Sonal Intertrend makes sports socks with a cotton yarn called velvet-teri that it developed in-house. This finer variety incorporates 25 percent super-combed cotton yarn.

The socks are knitted on 168-needle machines. They come with a complete heel, unlike other sports socks that do not have a heel. India-based Sinhal Overseas offers healthful socks with loose tops and gradated tightness for people suffering from diabetes and high blood pressure. The company's models with small cotton-spandex nets on the sides allow the feet to breathe. Its cushioned designs provide better comfort and shock absorption.