WHY SOCK CONSTRUCTION MATTERS IN FOOT CARE AND COMFORT

Your feet may be the hardest working part of your body. They bear the entire weight of your body for every minute you are standing, walking, running, jumping, etc. and, together with the ankle, contain more than 26 bones, 33 joints (20 of which are actively articulated), and more than a hundred muscles, tendons, and ligaments. Bearing all this weight, maintaining balance and assisting in movement, the feet cannot be blamed for sweating a lot—up to a cup a day for an average male—from their 250,000 sweat glands. So where does all of this moisture go? Not surprisingly, it is trapped inside the shoe and largely absorbed by the sock because many modern shoes do not “breath.” And there the moisture stays, providing the perfect environment for bacteria to grow---UNLESS the sock is able to transport the moisture up and out of the shoe or the shoe is, unlike most, well ventilated. Bottom line: socks can help you keep your feet healthy by reducing or removing the moisture that BACTERIA need to grow in and that cause BLISTERS in areas experiencing abrasion.

HOW DO SOCKS MANAGE MOISTURE?

Low and behold, reducing or transporting that moisture is a job that has been engineered into many modern socks by inventive US sock manufacturers. They have two basic approaches to managing moisture. One is to insulate the feet from temperature extremes and thereby reduce perspiration. The second is to devise methods of transporting moisture away from the foot. By combining materials and using special knitting patterns, some manufacturers attempt to do both. 

The insulation approach has historically been spearheaded by the proponents of natural fibers such as wool or alpaca. Some synthetic fibers achieve the same result with fiber structures that hold air, an insulator, in the sock surrounding the foot. See the sections below on those fabrics for further information and examples of products using this approach.

BEWARE, COTTON PICKERS.

The transport process is known as wicking. Lesson No. 1 is that it will not happen with socks made with a high cotton content. Cotton soaks up perspiration like a towel and holds it. Cotton fiber retains three times the moisture of acrylic and fourteen times the moisture of CoolMax®. When exposed to ambient air, socks composed of cotton retain moisture ten times longer than acrylic. Natural fibers (cotton-wool) when laden with moisture, compress more easily than synthetic fibers like acrylic and CoolMax®. Thus, cotton and wool socks have a higher resistance to sweat transport by wicking. When wet, acrylic fibers swell less than 5% while cotton swells 45% and wool swells 35%. Swollen fibers that are compressed reduce air spaces and thus reduce moisture transport. It's no wonder that cotton socks exhibit a 2.4 times higher resistance to moisture transport than acrylic. Cotton also tends to stretch and flatten out under the weight exerted by the body. Cotton loses all resilience when it becomes wet, ceases to cushion the foot and can become the source of blisters where it forms creases within the shoe or wherever there is any friction in a wet environment. So Lesson No. 2 is: KEEP YOUR FEET AS DRY AS POSSIBLE BY AVOIDING SOCKS WITH HIGH COTTON CONTENT. Note, however, that small amounts of cotton in newer fabric blends can function as a way of drawing the moisture away from the foot.

One thing to note is that wool is not nearly as compressive as cotton and so, especially when plaited with nylon, if used adjacent the skin in a terry cloth-like knitting pattern, it may support fabric channels which allow for the flow of vapor (evaporated sweat) away from the foot.

SHOE AWAY MOISTURE?

Today, many of the shoes and boots we buy are made of synthetics that do not breathe. That means that even if you are wearing socks made of materials that wick the moisture away from your skin, there is usually only one way to vent that moisture—it must migrate up the sock and out the top of your shoe or boot.

TECHNOLOGY TO THE RESCUE.

The American sock industry pioneered the use of synthetic fabrics to wick moisture away from your skin and special fabric combinations and knitted structures to channel moisture out the top of your shoe. The knitted structures are also intended to provide added support, to prevent the sock from sliding around on your foot—a potential source of discomfort and blisters-- and improve the way the sock conforms to the contours of your foot. As noted above, the structures may also provide small spaces that channel moisture away. Studies by the Marine Corp in the ‘90s found that synthetic yarn knitted with small loops, a bit like terrycloth, provided a cushioning and moisture transport environment that significantly reduced the incidence of blisters and enhanced comfort. A resilient fabric knitted into a cushioning structure can also protect your foot from some aspects of an imperfect fit of the shoe or boot. Lesson No. 3: LOOK FOR SOCKS WITH INTELLIGENT CONSTRUCTION WHICH AIDS IN KEEPING YOUR FEET DRY AND CONFORTABLE and also provides some CUSHIONING for activities like hiking. To do this, you have to look at the INSIDE OF THE SOCK.

SOCK SLEUTHING.


Ok, so to determine if the sock construction is good for you, you need to check out two things. FIRST, check the label for the material content. It is often hidden away on a side panel, but it is there. Find it and then use the information below about materials to understand how the materials may affect your feet during use. SECOND, check out the INSIDE of the sock. The outside is usually pretty to the eye and may be built to help the sock better withstand abrasion, but the inside is what your feet will feel. So turn the sock inside out if possible, or stick your hand down inside—is this getting a little steamy? Don’t be alarmed if you see the long ends of some of the yarn exposed on the inside—it shouldn’t bother you or affect sock performance. It is like looking inside your computer—a little scary, but most of what you see is there for performance.

THE INSIDE STORY ON SOCK CONSTRUCTION

Ok, as you look inside, you need to (A) see or feel the softness and cushioning surrounding the pressure points on your foot—some sock are built with light or no cushioning for those who prefer a very snug fit to the shoe. The heel, bottom and toes of the socks are where the cushioning is usually built in. You should see or feel the cushioning-- knitted-loops mentioned above. (B) The ankle section and top of the foot are usually built to hold the sock up and to help ventilate the foot. (C) The mid-foot section may be knitted with some elastic fabric to compress the sock around your foot and prevent the sock from sliding around. (D) Finally, the toe closure—where the top of your toes meet the sock—should be smooth, NOT bulky. This is called the “toe closure.” Years ago, machines knitted the sock leaving the toe open, and then the toe had to be stitched closed in a separate operation that left a very pronounced seam at the toe that could prove irritating, or at minimum, uncomfortable, especially in something like a running or hiking sock. The latest sock knitting machines can knit a very smooth closure now. So make sure you look for a smooth toe closure.

SO IF NOT COTTON, THEN WHAT?

The alternatives to cotton are typically some combination of the following: Wool, Alpaca, Acrylic, Elastic, Nylon, stretch nylon, Olefin (aka polypropylene), Polyester, and Spandex. Note that hydrophobic means repelling water and hydrophilic means attracting or absorbing water.

Natural Fibers

  • Wool is an excellent natural fiber and is sometimes woven with nylon on the outside (Outer Nylon Plaiting) to make it wear longer. It is a great insulator and can absorb up to 30% of its own weight in water before it feels damp. It retains its insulating properties even when wet. It does not crush like cotton when wet but it does not wick moisture particularly well on its own. However, knitting small loops on the inside of the sock improves ventilation, cushioning and moisture flow. It is a fabulous cold weather fabric because of its insulating properties, which, with thinner knits, may also insulate the foot from warmer temperatures. Most wool socks have at least a 20% nylon content to improve wear. Many manufactures combine wool with other synthetics to better manage moisture and wear. Higher end socks generally use
  • Merino wool because it is one of the softest types of wool available, having fibers that are finer with smaller scales, which reduces or eliminates the “itchy” feel normally associated with wool. American Merino wool is a bit curlier than the “down-under” variety but, grade for grade, functions equally well. The packaging won’t tell you much about the grade of wool used in the sock. The longer stranded wool is more highly prized because the yarn then has fewer fiber joints that could fail. The finer stranded wool is more highly prized because it allows for a softer feel and denser, more durable knit.
  • Alpaca fiber is extraordinarily soft and many times stronger than Merino wool. Its hollow-cell structure provides superior insulation from heat and cold, the fibers resist compression and have a very low scale height making them extremely smooth thereby reducing friction and the resulting blisters. It needs no special care though we recommend hang-drying all quality socks.
  • Silk is a very smooth, soft fiber with high tensile strength that does not conduct heat and which has some antimicrobial and odor-reducing properties. This is a natural fiber, like wool, but made by silk worms.
  • Bamboo is a plant that can be converted into a soft, comfortable fiber. However, the conversion process is said to be environmentally unfriendly. As a result, we have chosen not carry socks with bamboo content.

Synthetic (man-made) and blended fibers and composition.

  • Acrylic is a light-weight synthetic (man-made) fiber featuring both softness and warmth as well as high durability and the ability to hold bright colors. It tends to dry quickly and can be used in wicking sections of socks. There are some blended, branded versions of acrylic that provide some very advanced features. We think acrylic’s resilience makes it great for cushioning the foot. Because it does not absorb water, it helps keep the feet dry and does not tend to create the odors associated with some synthetics.
  • Nylon is a very strong, versatile and hard wearing fiber that can be silky thin or bulky. It is often used with other fibers to provide added stretch or durability. Nylon is a component in almost all modern socks, whether interwoven with natural fabrics or as a strengthening or stretching material. When nylon fibers are crimped and heat set, they become elastic and can then be used to provide the stretch feature of socks.
  • Polypropylene/Olefin is a superior water repelling fiber (hydrophobic) that is used with absorbent outer layers to wick moisture away from the skin. It is one of the strongest and lightest of the synthetic fibers but is easily damaged by heat.
  • Polyester & stretch Polyester are hydrophobic fibers known for their durability and colorfastness. This material is usually bended with other fibers to maximize the functionality of the sock. It has been used to create many special purpose and branded fibers such as:
    • 4-channel polyester (think of it like little hollow tubes) is a high-performance synthetic designed to facilitate the movement of moisture and perspiration, termed “wicking,” and is fast drying.
    • Coolmax ™ is a branded 4-channel polyester that is superior for wicking and fast drying. For some people, it can make the feet feel a bit hot. We think it is best used in a fabric blend. Our experience is that when used alone, it can reflect heat toward the foot and can sometime generate unpleasant odors after wear.
    • Hollofil™ is a very light-weight polyester made with a hollow core which provides warmth and loft and is usually blended with other fibers.
    • Dri-release ™ is a patented technology which layers a hydrophobic material next to the skin which then pushes moisture to an outside hydrophilic layer. It generally consists of a high percentage of polyester combined with a small amount of cotton or rayon to pull moisture away from the skin. Seems to work well and offers odor management as well.
    • Spandex ™ and the branded Lycra ™ are elastic, synthetic fiber used in place of rubber in the arch and legs of socks to hold them in place and provide extra support.

In any event, we think socks are such an important element of clothing that the consumer should be careful to buy and use the best possible socks. You will be rewarded with surprising comfort and health. We also believe that Socklinks ™ are vitally important in justifying the purchase of quality socks because they allow the consumer to get many times their money’s worth by preventing loss, simplifying the cleaning and drying process, saving energy and reducing the damage dryers cause to the elasticity of socks. Our sales pitch, buy Paired Socks™ from Link2sox and put an end to the hassles caused by unruly pairs of socks that seem to repel mates.

CONCLUSION

Among sock manufacturers, Merino Wool (and similar fabrics like Alpaca), nylon and polyester have become the go-to fabrics for the majority of the performance and comfort socks on the market. Modern knitting machines have allowed the manufacture of socks in a wide variety of patterns and cushion levels and in a way that allows the use of different knit patterns and fabrics for each different section of the foot—the bottom of the foot can have different levels of cushioning, the heels and toes made for better wear and to reduce friction, the top mid-section of the foot for ventilation and compression to prevent sliding and sagging. Expect to see these capabilities used in your performance socks.

Use the above information to make intelligent selections when buying socks. Link2sox.com has used this information to select socks that will perform at a high level for its customers. We test dozens of socks before selecting the ones which we sell on our site. We try to identify socks that perform exceptionally well at various price points. READ OUR DESCRIPTIONS OF SOCKS ON THE WEBSITE AND PAY CAREFUL ATTENTION TO THE FIBER CONTENT.

Thanks for taking the time to read and understand this information. Please use the CONTACT tab to keep us abreast of your comments, suggestions and experiences. We are listening and striving to provide you with the best products possible.