Layered clothing
Encyclopedia
Layered clothing is a manner of dressing using multiple garments that are worn on top of each other. Some of the layers have different, largely non-overlapping, functions. Using more or fewer layers, or replacing one layer but not others, allows for flexible clothing to match the needs of each situation. Two thin layers can be warmer yet lighter than one thick layer, because the air trapped between layers serves as thermal insulation
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Layered clothing is particularly relevant in cold climates, where clothing must at the same time transfer moisture, provide warmth, and protect from wind and rain. In a hot and dry climate, clothes have very different functional requirements: they must block the radiation from the Sun, and allow for sufficient air circulation. Therefore, layered clothing in the sense used in this article is largely irrelevant to hot and dry climates.
Outdoor and sports wear manufacturers favor layered clothing because, among other reasons, it allows them to offer so-called "technical" or "functional" clothes which are optimized for the particular demands of a specific layer. Such clothes are often made of advanced synthetic materials, and can be expensive.
Often clothes combine two adjacent layers, as in the case of warm undergarments that provide both comfort and insulation.
. This is sometimes called wicking, and thus the used materials are called wicking materials. When moisture has moved from the skin into (nonabsorbent) clothing, it has more surface area and will evaporate faster. If a piece of clothing does not transfer moisture well, it is not strictly an inner layer garment at all, but simply a comfortable mid-layer garment.
. One thick layer works better for maximum warmth, but the use of multiple thin layers facilitates adjustment of warmth. The mid layer should be more loose-fitting than the inner layer, as this leaves insulating air between the layers. However, if best possible moisture transfer is desired, too great a gap between any adjacent layers of clothing may reduce the moisture transfer by capillary action from one piece of clothing to another. On the other hand, very loose-fitting layers can allow more removal of moisture (and heat) via air circulation.
The outermost clothes are called the shell layer, but only if they block wind or water, or have good mechanical strength. Ideally the shell layer lets moisture through to the outside (that is, is breathable), while not letting wind and water pass through from the outside to the inside. While this is enabled to some degree by modern materials, even the best and most expensive materials involve a trade-off between breathability and water- and wind resistance.
If heavy sweating is expected, one should avoid wearing any shell layer garments unless their protective properties are essential. For example, when one is jogging, no shell layer is likely to be able to transfer enough moisture to keep the wearer feeling dry. Instead, one should consider using sufficiently warm mid layer clothes.
The term Soft Shell is increasingly used to describe garments that combine partial water resistance with partial wind breaking ability. Soft shell fabrics come in numerous varieties with many garments offering a combination, such as a wicking layer. In many cases insulation is combined in an attempt to replace several layers with a single highly flexible one.
Dressing in layers probably dates back many years, perhaps many centuries, but its recent revival in fashion stems from the 1960s and 1970s when the hippies or street people, so called bums, discovered that layering was inexpensive, very effective, and comfortable. By the early 1970s a number of entertainers had adopted the dress and it has spread to many other walks of life since that time, largely because it has proven to be quite effective.
Thermal insulation
Thermal insulation is the reduction of the effects of the various processes of heat transfer between objects in thermal contact or in range of radiative influence. Heat transfer is the transfer of thermal energy between objects of differing temperature...
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Layered clothing is particularly relevant in cold climates, where clothing must at the same time transfer moisture, provide warmth, and protect from wind and rain. In a hot and dry climate, clothes have very different functional requirements: they must block the radiation from the Sun, and allow for sufficient air circulation. Therefore, layered clothing in the sense used in this article is largely irrelevant to hot and dry climates.
Outdoor and sports wear manufacturers favor layered clothing because, among other reasons, it allows them to offer so-called "technical" or "functional" clothes which are optimized for the particular demands of a specific layer. Such clothes are often made of advanced synthetic materials, and can be expensive.
Layers
Usually at least three layers are identified as follows:- Inner layer provides comfort by keeping the skin dry. Also called base layer or first layer.
- Mid layer provides warmth. Also called insulating layer.
- Shell layer protects from wind and water. Also called outer layer which works as protection over the other two layers.
Often clothes combine two adjacent layers, as in the case of warm undergarments that provide both comfort and insulation.
Inner layer
The purpose of the inner layer is to draw the sweat away from the skin to the next layers, which makes the wearer feel warmer and more comfortable. The transfer of moisture happens due to capillary actionCapillary action
Capillary action, or capilarity, is the ability of a liquid to flow against gravity where liquid spontanously rise in a narrow space such as between the hair of a paint-brush, in a thin tube, or in porous material such as paper or in some non-porous material such as liquified carbon fiber, or in a...
. This is sometimes called wicking, and thus the used materials are called wicking materials. When moisture has moved from the skin into (nonabsorbent) clothing, it has more surface area and will evaporate faster. If a piece of clothing does not transfer moisture well, it is not strictly an inner layer garment at all, but simply a comfortable mid-layer garment.
- Synthetic materials such as polyesterPolyesterPolyester is a category of polymers which contain the ester functional group in their main chain. Although there are many polyesters, the term "polyester" as a specific material most commonly refers to polyethylene terephthalate...
and microfiberMicrofiberMicrofiber or microfibre refers to synthetic fibers that measure less than one denier. The most common types of microfibers are made from polyesters, polyamides , and or a conjugation of polyester and polyamide.Microfiber is used to make non-woven, woven and knitted textiles...
-based fabrics are good choices as they do not absorb moisture but may transfer it well. They can also carry specialist finishes, such as anti-bacterial agents which reduce odours, and insect repellent.
- WoolWoolWool is the textile fiber obtained from sheep and certain other animals, including cashmere from goats, mohair from goats, qiviut from muskoxen, vicuña, alpaca, camel from animals in the camel family, and angora from rabbits....
has fairly good wicking properties. How comfortable wool feels against skin varies greatly, from very rough and itchy to comfortable. Wool doesn't start to smell as quickly as synthetic materials.
- SilkSilkSilk is a natural protein fiber, some forms of which can be woven into textiles. The best-known type of silk is obtained from the cocoons of the larvae of the mulberry silkworm Bombyx mori reared in captivity...
feels comfortable, but is weaker and harder to take care of, and is less commonly used.
- CottonCottonCotton is a soft, fluffy staple fiber that grows in a boll, or protective capsule, around the seeds of cotton plants of the genus Gossypium. The fiber is almost pure cellulose. The botanical purpose of cotton fiber is to aid in seed dispersal....
is cheap and feels comfortable when dry but absorbs moisture easily and is slow to dry out, especially in cold conditions. Cotton is better suited for the middle layer.
Mid layer
The mid layer is needed in cold weather to provide additional insulationThermal insulation
Thermal insulation is the reduction of the effects of the various processes of heat transfer between objects in thermal contact or in range of radiative influence. Heat transfer is the transfer of thermal energy between objects of differing temperature...
. One thick layer works better for maximum warmth, but the use of multiple thin layers facilitates adjustment of warmth. The mid layer should be more loose-fitting than the inner layer, as this leaves insulating air between the layers. However, if best possible moisture transfer is desired, too great a gap between any adjacent layers of clothing may reduce the moisture transfer by capillary action from one piece of clothing to another. On the other hand, very loose-fitting layers can allow more removal of moisture (and heat) via air circulation.
- WoolWoolWool is the textile fiber obtained from sheep and certain other animals, including cashmere from goats, mohair from goats, qiviut from muskoxen, vicuña, alpaca, camel from animals in the camel family, and angora from rabbits....
is the traditional mid layer material with several good properties: it has good insulation even when wet, absorbs moisture but does not feel wet even when it holds significant moisture, and transfers moisture.
- FleecePolar fleecePolar fleece, usually referred to simply as "fleece," is a soft napped insulating synthetic fabric made from Polyethylene terephthalate or other synthetic fibers. One of the first forms was Polar Fleece created in 1979 by Malden Mills, now Polartec LLC., a new, light and strong pile fabric meant...
made from PETEPetePete is a diminutive from Peter. It may refer to:-Athletics:* The Pete, Petersen Events Center, athletics complex and basketball arena on the campus of the University of Pittsburgh* Pete the Penguin, mascot of Youngstown State University...
or other synthetics has many of the features of wool, but is lighter. It provides good insulation even when wet, absorbs very little moisture, and dries quickly. Although no longer commonly used in the industrialized world, natural sheepskin fleece could also serve the mid layer function.
- DownDown feathersThe down of birds is a layer of fine feathers found under the tougher exterior feathers. Very young birds are clad only in down. Powder down is a specialized type of down found only in a few groups of birds. Down is a fine thermal insulator and padding, used in goods such as jackets, bedding,...
has a very good warmth:weight ratio, and can be packed down (squeezed) to take very little room. On the downside, it is expensive, makes a thick garment, dries slowly, loses its insulating properties when wet or compressed, and stops lofting properly after being washed several times.
- Synthetic Fiberfill such as polyesterPolyesterPolyester is a category of polymers which contain the ester functional group in their main chain. Although there are many polyesters, the term "polyester" as a specific material most commonly refers to polyethylene terephthalate...
fiber is used similarly to down, but does not have as good a warmth:weight ratio. However, it is less expensive, provides good insulation even when wet, dries quickly, and absorbs very little moisture. ThinsulateThinsulateThinsulate is a trademark of the 3M Corporation, for a type of synthetic fiber thermal insulation used in clothing. The word is a portmanteau of thin and insulate...
is a brand of very fine fiberfill that provides higher warmth for a given thickness.
- CottonCottonCotton is a soft, fluffy staple fiber that grows in a boll, or protective capsule, around the seeds of cotton plants of the genus Gossypium. The fiber is almost pure cellulose. The botanical purpose of cotton fiber is to aid in seed dispersal....
, as with the inner layer, is a cheap alternative, but a reasonable choice only when low insulation and moisture transfer is needed.
Shell layer
If heavy sweating is expected, one should avoid wearing any shell layer garments unless their protective properties are essential. For example, when one is jogging, no shell layer is likely to be able to transfer enough moisture to keep the wearer feeling dry. Instead, one should consider using sufficiently warm mid layer clothes.
- Plastic raincoatRaincoatA raincoat is a waterproof or water-resistant coat worn to protect the body from rain. The term rain jacket is sometimes used to refer to raincoats that are waist length. A rain jacket may be combined with a pair of rain pants to make a rain suit.Modern raincoats are often constructed of...
s protect completely from water and wind, but let through no moisture. To compensate for that, such raincoats usually have flap-covered holes and are very loose-fitting at the bottom to allow air circulation.
- Waterproof breathableWaterproof fabricWaterproof fabrics are fabrics that are inherently, or have been treated to become, resistant to penetration by water and wetting. They are usually natural or synthetic fabrics that are laminated to or coated with a waterproofing material such as rubber, polyvinyl chloride , polyurethane , silicone...
(hard shell) materials are waterproof and somewhat breathable. Their essential element is a thin, porous membrane that blocks liquid water, but lets through water vapor (evaporated sweat). The more expensive materials are typically more breathable. The best-known brand is Gore-TexGore-TexGore-Tex is a waterproof/breathable fabric, and a registered trademark of W. L. Gore and Associates. It was co-invented by Wilbert L. Gore, Rowena Taylor, and Gore's son, Robert W. Gore. Robert Gore was granted on April 27, 1976, for a porous form of polytetrafluoroethylene with a...
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- Water resistant (soft shell) materials block water only partially. On the other hand they are usually more breathable and comfortable, thinner, and cheaper than completely waterproof materials. Water-repellentDurable Water RepellentDWR is a coating added to fabrics at the factory to make them water-resistant . Most factory-applied treatments are fluoropolymer based. Durable water repellents are commonly used in conjunction with waterproof breathable fabrics such as Gore-Tex to prevent the outer layer of fabric from becoming...
coatings are often used. Before waterproof-breathable shells were invented, the "60/40" (60% cotton, 40% nylon) parka was widely used. Soft shells are not water "proof".
The term Soft Shell is increasingly used to describe garments that combine partial water resistance with partial wind breaking ability. Soft shell fabrics come in numerous varieties with many garments offering a combination, such as a wicking layer. In many cases insulation is combined in an attempt to replace several layers with a single highly flexible one.
Adjusting a layering system
As the intensity of exercise or environmental conditions change, the amount or quality of layers worn should be changed. In particular, if clothes become wet from sweating during heavy exercise, they can be much too cold during the following period of rest. Below are two basic strategies for this problem.Vents
Some clothes feature adjustable vents, such as below armpits. The positioning and design of the vents allow for area specific cooling while only marginally reducing exterior moisture resistance.Removing layers
Removing the shell layer during heavy exercise can pose problems if the clothes underneath lack required mechanical strength or water proofing. In such situations, using a mid layer with enough of the required shell layer properties can be a good choice.Fashion use
Combining different garments in layers can be used to create a variety of outfits. This provides similar practical benefits to practical layering, in that the wearer can shed layers according to changes in temperature, and is also a way of making use of clothing to produce different looks and mix colours in various ways.Dressing in layers probably dates back many years, perhaps many centuries, but its recent revival in fashion stems from the 1960s and 1970s when the hippies or street people, so called bums, discovered that layering was inexpensive, very effective, and comfortable. By the early 1970s a number of entertainers had adopted the dress and it has spread to many other walks of life since that time, largely because it has proven to be quite effective.