The basic benefits of woolly thinking

The days of crunching across stubble after early-season partridges with sunburned cheeks are drifting away. We can no longer expect to be tramping around the hills in pursuit of stags in our shirtsleeves. It is time to put our summer wardrobe into mothballs and dig out the attire that will keep us warm through the grey months, when despite the howling conditions, we sporting sorts refuse to be cowed into remaining indoors. 

Keeping warm and dry in horrid weather across challenging terrain is a tall order and from childhood I have been reliably informed that success in this endeavour is all about layers. The first, and possibly most important, stratum of clothing is the base, or thermal layer. 

The Inuit people and a raft of other circumpolar tribes have been experts in thermal layering. They developed ingenious ways to keep the cold at bay without getting too sweaty while out hunting megafauna on the ice floes and tundra. It was well known for Inuit to wear up to five layers of socks, including stockings with attached feet called aliqsik or mirquliik. These were usually made of reindeer, polar bear or ringed seal skin, with the fur facing inwards. 

Polar bear skin might be slight overkill for autumn roe stalking in the Cotswolds, even if the weather is really gopping, but it represents some of the earliest thermal clothing for use in the hunting sphere. 

Later developments in thermal wear that grew in popularity in the industrial age were long johns and the all-in-one union suit. The former rose to popularity in Britain towards the end of the 18th century, when they were mass produced by John Smedley’s Lea Mill in Derbyshire. John Smedley still makes long johns today. 

A lot of these early thermals were made from cotton, which readily absorbed sweat, so the wearer quickly becomes uncomfortable and eventually cold. The enormous benefit of modern thermal clothing, made from synthetic fibres or wool, is its moisture-wicking ability. 

Moisture-wicking appears in the bumph of almost all thermal wear, but its meaning and physical properties are nuanced. Moisture management is a functional property of textiles that enables them to transfer moisture from the skin by capillary action through the fabric, spreading it over a large external surface area, which helps it dry quickly. It sounds obvious that the better the wicking, the better the thermal layer — but that is also not the case. 

Synthetic 

Following the refining of the production methods of polyesters and other synthetic fibres in the 1940s, there was a slow progression of their uses in clothing. By the 1980s almost all base layers were made of synthetic fibres. Such fibres are far less absorbent than wool, dry faster and disperse moisture faster. But while this sounds like a win on all fronts, synthetic fibres lose out to natural ones in a variety of areas. 

If you are simply wanting to stay cool while indulging in sustained physical activity, then synthetic fibres are the right choice. So for trail running or activities such as sailing, where there are going to be consistently high moisture levels from sweat or atmospheric conditions, synthetic materials are superior because they dry out fastest. 

Activities like shooting or stalking, characterised by periods of mid-intensity activity followed by prolonged periods of inactivity, benefit from the properties of wool. 

Wool has greater insulative properties per gram than synthetic fibres so will keep you warmer than a synthetic base layer of the same weight. Like synthetic fibres, wool is excellent at dispersing moisture, but it absorbs some of it which then evaporates more slowly. This means the cooling effect is gradual. Wool therefore tends to do a better job as a thermoregulator for the human body. 

If you were to walk up a steep hillside on a stalk, perspiring heavily, then pause at the top to glass the surrounding hillsides, a woollen thermal layer would continue to keep you warm as the sweat slowly evaporated. But a synthetic base layer would allow the moisture to evaporate quickly, causing convection currents that could leave you feeling chilly during your period of inactivity. 

Wool from merino sheep, which originated from the mountainous regions of Spain, is the finest of all wool. It has a diameter several times smaller than that of a human hair. This means it is not scratchy to the touch, and it is able to trap more air than other wools. Unlike synthetics, it carries no electric charge, and its exterior surface is scaly in texture. 

Synthetic materials like polyester have smooth surfaces with positive charges, which more readily attract odour-producing bacteria. Merino wool in particular is almost odour-free. Last year, I wore a merino base layer for two months solid with about one shower a week on a kayaking trip down the Danube from Germany to Romania. By all accounts I should have smelt like a rutting billy goat. But the magic of merino wool meant I smelled a bit stale. 

Durability 

Sitka Gear brand ambassador Chris Dewbury is passionate about layers. “If you don’t set a good foundation then everything else you wear doesn’t perform like it should,” he says. Sitka Gear is owned by industry giant Gore-Tex and thus has access to its innovative proprietary materials. These include its durable Cordura blended four-way stretch fabric, which Sitka uses in its synthetic range. Products made from this material offer unparalleled freedom of movement and durability. 

Sitka has also developed an extraordinary range of merino base layers using Armorspun technology. This is modern material science at its finest. Armorspun merino involves an industrial process in which nylon is wrapped around the natural merino wool fibres, vastly improving the wool’s longevity and making it more impervious to abrasion. This triumph of technology really does represent the best of both worlds. 

Swedish thermal expert Woolpower has come up with its own unique material based around merino wool. Its Ullfrotté fabric is two-thirds merino and the rest polyamide and polyester, as well as 5% of elastane to give an outrageous range of movement. 

The brand sent me a few of its items to test and they are utterly superb. The Crewneck 200, as its name suggests, weighs barely 200g but keeps you toasty while sitting still and somehow stops you from overheating when you are dragging a stag off the hill. It’s like having a second skin. The inside has a fabulous sort of merino fleecy effect that lifts the garment a few millimetres from your skin to trap a little extra air and prevent you from becoming clammy. 

Ash Shaw, who represents the Kymira range, also believes that the right base layer is the foundation for your outdoor attire, providing essential benefits that directly impact your comfort and performance. 

Kymira products, like many of the other base layers, are masters of moisture management, temperature regulation and managing the smooth interface between your skin and your outer layers. However, Kymira base layers benefit from its own proprietary technology. 

The brand’s Charge Infrared Compression Leggings absorb the energy your body emits during activity and converts it into infrared radiation, which is then reflected back into your body tissues. Alongside targeted insulation and compression, the base layers are said to improve blood circulation and oxygenation, reduce inflammation and even promote the breakdown of lactic acid. 

The same technology is already being utilised by Olympic sports stars and Premier League footballers — think of the benefits it could offer on a strenuous walked-up day. 

“Kymira’s range of base layers ensure comfort whether shooting in the cool morning or midday sun, allowing focus on shooting, not the weather,” Ash sums up. 

Perdie Reid, UK PR manager for Seeland and Härkila, says: “At Härkila, we understand that base layers are the foundation of comfort and performance for outdoor stalking and shooting activities.” She was keen to stress that base layers take care of physical comfort, allowing stalkers and shooters to focus their full concentration on the hunt. 

Härkila has an exceptionally versatile range of thermal clothing and Perdie emphasises that fit for base layers is of the utmost importance. “No matter the thermal and moisture-wicking properties of the garment material, if the layers do not fit well then they cannot trap air in the designed way and thus do their job,” she explains. 

Stop-start 

Seeland also has a variety of base layers that accurately match a range of activities and their intensities. The Seeland Climate base layer is 100% merino wool, so is better suited to a stop-start hunt, when you need the garment to cool you on the move and keep you warm when you stop for extended periods. Seeland’s Hawker base layer is half-and-half merino and polyester and is more suited for consistent movement. 

Whether you are sitting in a frosty high seat hoping to spot a boar, or striding across a sun-drenched moor for walked-up grouse, there is a base layer to suit your needs. And with the advances in fabrics, there has never been a better time to invest.