We had a tradition to name functional linen for occupations by sports by a word "thermo underclothes". It is not absolutely correct, but the tradition is tradition. The prefix "thermo" confuses the buyer and frequently asked: "As this linen is strong heats?" Or "At what temperature to me it will be warm in this linen?" Except for warming the functional linen can carry out still set of other functions, but times has developed "thermounderclothes" so let for simplicity and will be. But it is not necessary to forget, that "the Functional linen" is more correct.

1. Classification as a material (it is not dependent on thickness) Functional linen can be executed from polyester (lavsan), polypropylene, a wool, a cotton or their mixes. Only synthetic materials remove moisture better, are more durable. Addition of cotton or wool makes linen by more pleasant in wearing. The modified polypropylene for today the most successful material for linen - it has practically zero absorbency and consequently in the best way removes moisture.

The functional linen can carry out some functions - to heat, remove moisture or both that and another at once. At physical work the skin of the person allocates enough plenty of moisture which collecting in a fabric of usual linen sharply reduces it thermo-insulating properties plus is spent for warming and evaporation of this moisture to this additional energy. It is especially appreciable at occupations by water kinds of sports when the moisture gets also from the outside. Here important there is that, for example polypropylene at all does not absorb water, and you do not spend energy for warming of this water - it quickly flows down also linen dries up for few minutes even on a body, without sensation of discomfort. I.e. the modern functional linen effectively removes moisture from a body (either in an atmosphere, or in external layers of clothes), that reduces of heat loosing an organism in cold weather and adds sensation of comfort. Series of linen of the increased thickness except for removal of water have a sufficient thermo-insulating property that allows using them as sweaters.

Traditional variant of use of functional linen is its use as the first layer in multilayered system of clothes It is the system of clothes standard on today, which means use several (from 1 to 3-5) layers of clothes where the basic purpose of the first layer is removal of a moisture from a body, the following layer is usually carried out from Polartec and provides thermo regulation and the following provides protection against a wind and an atmospheric precipitation and is carried out from membrane fabrics such as Gore-Tex. Various intermediate variants are possible also.

Let's consider in more detail various kinds of functional linen by the example of the Czech firm "TG 900 Moira". Production of this firm is well-known in Russia, is in demand the deserved demand and has very good responses at buyers. This firm makes some series of functional linen: Ultra Light, Mikro, Mono, Duo, Trio, Plys.
Ultra Light - the most thin and easy series of linen intended for carrying it is direct on a body. It can be applied in a hot season. Very well removes moisture from a body material of 100 % the modified polypropylene.
Mikro - the series of linen developed specially for everyday carrying. Well removes moisture from a body a material of 100 % the modified polypropylene.
Mono - a series of thin linen for extreme sports. Very well removes moisture from a body material TG900 with antibacterial processing.
Duo - the most universal series of linen the special weaving of the fabric forming the increased air layer. Very well removes moisture from a body and has average thermo-insulating properties material TG900 with antibacterial processing.
Trio - the warmest series, on thermo-insulating does not concede fabric Polartec 100 material TG900 with antibacterial processing.
Plys - a series is intended for use in a combination to linen Duo in conditions of very cold weather a material - the modified polypropylene with addition of cotton.

Properties of thermo underclothes depend on five components: structure of a fabric, weaving of a fiber, weaving of a fabric, type of processing, breed and quality of tailoring.
Structure of a fabric - as it has been already told, one of the best materials for today is polypropylene. Concedes to it polyester a little.
Weaving of a fiber - practically all modern fabrics for thermo underclothes are executed from a microfibre is very thin fiber of various sections which, being plaited in a fabric creates unique sensation of comfort due to high density of fibers.
The type of processing - qualitative linen necessarily has special antibacterial processing for reduction of an unpleasant smell at long wearing. On a background of usual impregnations fiber TG900 (from which linen Moira is executed) is allocated. Granules with antibacterial structure are included in structure of a fiber and provide more long action. But, unfortunately, all these structures are not so durable and after 2-5 washings are washed away - as to not erase linen will fail.

1. If you need linen for daily wearing that is possible to choose practically anyone - woolen, with addition of cotton, only synthetic, etc. It is necessary to not be mistaken only with a choice of thickness - thin linen for warm time, thick for winter.
2. If you the sportsman the mountain skier, snowboarder or are fond of winter fishing a correct choice will be, both linen with addition of natural fibers, and only synthetic. For you important is, as ability of linen to remove moisture, and it thermo-insulating properties.
3. If you the climber, the tourist, sailor your choice is limited 100 % to synthetic fabrics and in the winter and in the summer. Only such linen is capable within many days at continuous wearing to provide comfort and is warm.
And once again about the main thing: the functional linen first of all should is effective to remove moisture from a body is its main task. To achieve heat it is possible and with the help of powder-puff, but it will not replace qualitative linen.

In the world set of firms make functional linen: TG 900 Moira, Litex, Levron, Helly Hansen, Craft, VauDe, Lowe Alpine, Big Pack and many others. Quality of linen of these and other dear firms very highly and on property they differ very insignificantly that it is impossible to tell about the price. For example, the complete set shirt + trousers Moira costs 44 $ and Helly Hansen is about 100$. It does not reflect a difference in quality and properties - the price depends on a marketing politics of firms of the manufacturer and the seller and from promotion of the trade mark.