Wool? Cotton? Synthetic? One pair? Two pairs? One thick pair and a thin-liner sock? Everybody seems to have their own preference, and like shoes, it depends a lot on the activity you are going to be using them for. Socks provide an interface between your foot and the shoe, the main functions being to pad the foot, protect from friction which helps prevent blisters, deal with sweat, and provide insulation.

Wearing shoes without socks is not ideal due to hygiene. Your feet perspire a lot so socks need to handle quite a lot of sweat as well as bacteria, and fungi, which can cause tinea and other infections. Socks can be changed and easily washed whereas shoe are not so easy to clean or disinfect.

The significant difference between socks is the fibre that they are made from. All socks have different blend of fibres, most containing some nylon, elastin or spandex for stretch and strength. . Cotton is excellent for making towels as it accumulates and holds moisture, but it is generally not so good for socks in this context.

Cotton socks, while good for day-to-day activity, tend to “bunch” under the foot and toes when damp with sweat, creating pressure points. Cotton can also become quite abrasive when wet. For everyday use, cotton feels cool and comfortable and can generally cope with the amount of moisture your feet will create. As you exercise, your feet will sweat quite a lot, so during more vigorous activity, acrylic seems to be the best way to go, particularly for blister prevention.

Acrylic socks, wear very well and commonly used in sport socks. Research comparing cotton and acrylic socks in long-distance runners found that acrylic socks significantly reduced friction blisters. Many people involved in outdoor sports are familiar with the benefits of acrylic thermal clothing.  Acrylic fibres help promote “wicking” moisture away from the skin’s surface to the outside environment, which helps keep the skin dryer. Acrylic socks have quite good thermal properties, and some socks designed for use in cool climates use a blend of hollow core polyester to give additional insulating properties.

“CoolMax” is a polyester blend manufactured by DuPont, which makes many technical fabrics. Coolmax is often used in sports clothing as it is very light, has good wicking ability, and assists in cooling. It is also used for lightweight socks suited for running activities in warm climates.

Wool is still the best fibre for socks in cool or cold climates. Apart from its thermal insulating properties, dry wool is hygroscopic and will absorb 30% of its weight in water vapour. Water molecules attach to sites within the wool fibre itself, and during this process, heat will be generated. A peak is reached within a few minutes and decreases over a few hours until equilibrium is reached. Research by the CSIRO division of textile physics has shown that saturating 1kg of dry wool generates 960 Kilojoules. This “heat of sorption” effect can be used in cold climates by packing woollen socks that have been dried in a sealed plastic bag, which will provide a natural source of heat when exposed to a moist environment, increasing the apparent insulation of the fabric. The wet insulating property of wool is also slightly better than that of polypropylene and acrylic.

Spotswood is a blend using superfine Marino wool, which is meant to effectively transfer moisture for high activity levels in warm climates without being too hot or itchy. Quite a few hiking socks are a blend of wool and acrylic or wool and silk to provide a good compromise of insulation and blister reduction.

Wearing two pairs of socks while doing activities like bushwalking and trekking has been common for years. Specifically designed liner socks are now available. These thin socks provide additional blister protection, insulation, or moisture control depending on the material they are made from, which includes CoolMax and acrylic.

As more technical materials are developed, socks, like shoes, have become very sport specific. Good quality sports socks are no longer tubed with a heel and toe. They are very anatomic in their shape, and some even have left and right feet. Most have additional fabric of differing amounts and types where you need it, such as under the ball of the foot, around the heel and the toes, with less fabric in the arch and over the instep to reduce bulk and allow the shoe or boot to fit more snugly. Some of the bulkier padded socks when you turn them inside out look frayed, but this is the type of construction is used to minimize the thickness of the seam, which helps eliminate pressure points.

Mountaineering and ski socks may also have additional padding around the shin to prevent the “boot bang” that can occur with rigid plastic boots.  Movement of the feet and socks within a shoe or boot will create a pumping action that will make some air movement, which helps remove moisture. Some newer, more technical socks incorporate additional channels to assist air movement.

Good socks come at a price, however, so be prepared to shell out at least $25 – $45 or more for a pair, but they do last a long time if you look after them.