Discover Serigena™ High-Performance Silk Base Layer
If you are searching for High Performing Thermal Baselayer, you have arrived at the right place. Serigena™ Silk Base Layer has some remarkably clever natural technical properties – super powers if you will – some that cannot be easily replicated with other baselayer.
It’s natural technical features include low bulk warmth™; dry air performance™, exemplary endothermic evaporative cooling™; intelligent adaptive insulation™; lightweight low bulk packability™; low friction freedom of movement™; smooth to the skin™ fabric; four way stretch for optimised movement™; shape retention & resilience™; wind chill reduction™; warm when it cools – comfortable when it warms™ ; optimised skin microclimate™; more action less odor™; good drying speed; flame and temperature resistance.
These technical features make Serigena™ Base Layer ideal for the mountains, arid regions, cool, cold, and dry weather, travel, adventure wear, and everyday living.
Fine silk knit undergarments are well known for their unmatched warmth as thermal layers for snow skiing. Read on to learn why and how you can leverage the same performance in your lifestyle
Polar Explorers and Mountaineers, have long considered Silk to be the premier high-performance next to skin technical base layer.
Read on to discover why:
Low Bulk Warmth™
Serigena™ Silk Baselayer Garments have a very high warmth to bulk ratio. You get more warmth and comfort for less space taken up under your clothing, with less restrictive bulk. See the performance metrics table below for a direct comparison of our silk base layer fabric thickness, warmth for weight, and thermal conductivity, against other base layer fabrics.
Fabric Type & Weight | Fabric Thickness | Warmth for Thckness (Bulk) | Thermal Conductivity (λ in W/m·K) of Raw Fiber / Filament |
Serigena™ Interlock Silk 75 - 80 GSM | Around 0.175 mm | High | 0.045 to 0.055 |
Ultralight Merino Wool 105 – 125 GSM | 0.30 – 0.45 mm | Medium | 0.035 to 0.054 |
Silkweight Polyester 100 - 130 GSM | 0.3 to 0.45 mm | Low | 0.15 to 0.25 |
- GSM = Grams per Square Metre i.e. the weight of a square metre of the garments fabric.
- Serigena™ Interlock Silk’s high warmth for thickness (bulk) ratio is due to the ability of its straight filament to densely pack flat, with a uniquely high ratio of micro and meso air voids within its low bulk thickness. The micro air voids – tiny, microscopic air gaps within individual silk yarn bundles contribute between 15% to 30% of the yarn volume. Meso-voids – the visible gaps between the knitted loops of the interlock structure contribute additional air gap insulation, and pathways for moisture transport. Together they provide a highly efficient low bulk thermal barrier, with excellent breathability. Conductive heat loss prevention by fabric is considered significantly influenced by the amount of trapped air within the fabric – in addition to the thermal conductivity of the fiber / filament. Trapped air has a very low rate of thermal conductivity (approximately 0.026).
- 100% merino wool is rarely knit below 120–130 GSM due to durability limits. It begins to become fragile below that weight – the thinner it is knit the more susceptible it is to tearing and holing. Merino wool’s insulation relies on its high loft (increased thickness), driven by its spring like crimped (wavy) 15 to 24 micron fibers (which cannot lay flat) and the air gaps between them.
- Silkweight polyester garment fabrics are designed to dry and cool the skin
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The lower the thermal conductivity number, the better the fibre acts as a thermal insulator preventing heat moving through garments
Dry Air Performance™
Polar Explorers and Mountaineers have long favored Silk Base Layers, Silk Glove Liners, Silk Balaclava’s, and Silk Sock Liners, for their elevated levels of activity in extreme conditions. Their exploration came with risks, and they knew how to reduce those risks.
Serigena™ Base Layer is superbly suited to elevated levels of activity in dry air conditions, wherever and when ever you experience them. You don’t need to be in the mountains to get the benefit of Serigena™ Silk Baselayer Dry Air Performance™. It works superbly well at lower altitudes in many climate zones that are prone to dry air, especially in cooler months and on cool days.
It will help understand this adaptation better if we quickly look at a conclusion drawn by researchers. Tanabe et al (2006) proved an important thermodynamic principle by their controlled experiment. In this, they moved twelve adults through two temperature chambers set at a constant 25.2 °C, with humidity conditions variously adjusted to 30, 40, 50 and 70% RH. The researchers found skin wettedness from perspiration is significantly lower at 30-40% RH than at 50 – 70% RH. They conclude the result proves evaporation of perspiration is greater in low humidities.
When you are active in low humidities you need a baselayer that will efficiently clear the increased amount of evaporation from your body when you perspire, and keep you warm when your body returns back to its equilibrium. We have just the thing for this in dry conditions with the Serigena™ Baselayer – it is made from the exemplar fabric for clearing increased evaporation in dry conditions. This process is known as endothermic evaporative cooling. Endothermic evaporative cooling involves liquid moisture from perspiration absorbing excess thermal energy from our skin and removing it through its transition into a gas and evaporation.
We are exposed to this dry air a lot more often than we generally realise.
To fully appreciate how the Dry Air Performance™ of Serigena™ Silk Baselayer can benefit our everyday life, it helps to know what causes ‘dry air’, and understand its physiological effect. The first useful thing to know is that temperature (and particularly the temperature of the air before it is heated by the sun) is often the best indicator of how dry the air is. As air temperature reduces it has reduced capacity to hold moisture – it becomes ‘drier’. The second thing worthwhile knowing is that dry air can be heated faster and higher (than moist air) by the sun. In many regions, temperate and arid, it is often the dryness of the air that leads to high diurnal temperature ranges – cold nights followed by hot days.
Dry air has many varied sources and causes. Arid regions for reasons of local climate and geography experience dry air for considerable periods of the year, some all the year long. Cold weather systems – atmospheric lows – originating in the high and low latitudes often bring cold dry air to nearby regions. Sinking air in atmospheric high pressure weather systems causes the air to dry. Adiabatic winds descending down mountain slopes (variously known as the Nor Wester, the Foehn effect, the Chinook, Santa Ana winds, Favonio etc) can dramatically lower the relative humidity of the air. Winds can can exacerbate regional conditions of low humidity by displacing moisture in the air. Very clear skies at night facilitating radiative heat loss can strip moisture out of the air by means of dew, or a frost, with a powerful drying effect. Heating our homes on cold nights lowers the relative humidity of air in our home that is already dry. When you ascend in the mountains by foot, train, motorcycle, or car, you will experience an increasing dryness of the air as your elevation increases. When you fly on a commercial flight you will experience very dry air.
Fortunately there are some simple rules of thumb we can use to assess how dry the air is. It’s worth realising all air at 15 deg C (absolute humidity 12.8 g/m3) is considered exceedingly moisture deficient, from a physiological perspective. That is significant considering temperate climates typically have a yearly average temperature of around 10°C (50°F), with temperatures averaging below 20°C (68°F) in summer, and 10°C (50°F) in winter. Strong winds can dry out the air even at summer temperatures. Mediterranean and inland Continental climates are cold and dry in winter. Air at 13°C (55°F) is considered dry. It becomes drier as the temperature reduces further.
As a rule of thumb, for every 11°C (20°F) drop in temperature, the moisture in the air is reduced roughly by half. So as temperatures approach a frosty zero °C (32°F), the air is becoming exceedingly dry. At and below that the tiny amount of remaining water vapor in the air has the tendency to crystalize into frozen forms.
Exemplary Endothermic Evaporative Cooling™
The key to Dry Air Performance™ is Exemplary Endothermic Evaporative Cooling™, enabled by the relatively high surface area of our baselayer silk. Silk’s high surface area (compared to the surface area of round to elliptical shaped merino wool fibers), attributable to the smooth, triangular cross-section shape of its filaments, enables increased skin to air vapor exchange, facilitating the acceleration of moisture evaporation rates when your body needs to cool itself through perspiration. The increased surface area allows excess heat to be pulled away from the skin by endothermic evaporative cooling.
Silk is considered the exemplar natural textile for endothermic evaporative cooling effect.
Endothermic evaporative cooling involves liquid moisture from perspiration absorbing excess thermal energy from our skin and extracting it in its transition into a gas and evaporation.
Intelligent Adaptive Insulation™
When we are very active when the air is dry, or dry and cold, we need a baselayer that can help cool us efficiently. Wouldn’t it be great though if the same baselayer could help keep us warm when our activity levels reduce . Well, it just so happens that our baselayer is able to do just that.
When temperatures fall towards 15°C (59°F), to 13°C (55°F), or further towards zero °C (32°F), or below, the dry air gradient accelerates the loss of moisture and body heat from our skin through a process called evaporative cooling. The tendency toward evaporative cooling is greatest in dry air, with a large vapor pressure gradient turning moisture on and inside our skin into gas rapidly, removing our precious body heat with it.
So as temperatures cool we get a compounded physiological effect – first we have the effect of the cold temperature on our bodies. Then at the very time we would prefer to retain the body heat we have, the dry air draws moisture from our skin, and with it our precious heat.
It’s a case of triple jeopardy – the cold air makes us feel colder; the dry air makes us give up our heat; and our cooling skin makes us feel colder again. When the dry and cold air is doing this, you need the heat retention properties of Serigena™ Baselayer next to your skin, and suitable mid and top layers above it.
Serigena™ Baselayer dry air performance™ and intelligent adaptive insulation™ make it the ideal baselayer for all round comfort during activity or rest in dry cold seasons, on cold days, and in the mountains and arid regions.
One of the remarkable things about silk is its thermal duality – its ability to quickly change from warming to cooling and back as our body needs. It picks up its cues for this from changes in the microclimate near our skin. Its like having a second skin™.
This Intelligent Adaptive Insulation™ performs particularly well in the dry environments the explorers and mountaineers pioneered.
Silks Intelligent Adaptive Insulation™ feature arises from its combination of a unique triangular filament structure, low thermal conductivity, and ability to rapidly process moisture vapor. These features enable it to dynamically alternate function between heat retention and evaporative cooling as skin surface humidity changes.
In a cooling / drying phase – when near skin humidity reduces, the body heat trapped by the thousands of micro air voids that accompany silk’s triangular filaments, meso air voids (the visible gaps between the knitted loops of our interlock knit fabric), and silk filaments low thermal conductivity, of Serigena™ Base Layer collectively minimise conductive heat loss from our skin.
If we then, in the same environment, warm up through activity and/or an increase in the days temperature, to a point where our body wants to cool itself, silk will draw moisture from the increased near skin humidity, through the meso-void gaps between the knitted interlock loops of the Serigena™ Base Layer, from the skin, and rapidly flash evaporate it to the dry air gradient around us. This enables our body to get the evaporative cooling it needs. In dry weather, this occurs with virtually no dampening of the fabric.
When our body has dissipated its excess heat and our near skin humidity returns to its equilibrium state, the silk filament, micro and meso voids, in Serigena™ Base Layer operate mainly in insulation mode, minimising conductive heat loss from our skin. This function makes silk perform incredibly well in dry environments, with activity levels ranging from low to moderate intensity aerobic, up to moderate to vigorous stop, go, stop type activities.
The ability of Serigena™ Baselayer fabric to quickly adapt to changing levels of humidity near your skin, and respond appropriatly to your bodies needs is a game changer.
Ultra Lightweight, Low Bulk Packability™
Our pioneering explorers and mountaineers had to reduce the load they carried to the minimum while increasing its utility to the maximum. Getting the balance right increased their chances of success – and survival.
Our silk base layer is very packable. For example, a Serigena™ Silk Baselayer Men’s Medium Long sleeve Top and Long pant set can together compress into a volume of around 0.6 of a liter (1.27 US pints), or to describe it another way, both can fit into a space the size of a typical trouser pocket with room to spare. Together they weigh around 255 grams (9oz).
Silk’s ultra-lightweight low bulk packability and high warmth ratio to weight, enables pack weights to be optimally low when every gram or ounce matters.
Low Friction Freedom of Movement™
These explorers and mountaineers are also widely believed to have prized the low friction freedom of movement that silk enables. Silk’s low friction co-efficient (it’s slipperiness) under the wool mid layers they wore would have reduced friction within the layering system considerably. Reducing system friction maximises freedom of movement and significantly reduces the energetic cost of movement.
In an endevour where every step counts, every ounce of energy used is accounted for, and chafing cannot be afforded, reducing movement friction becomes incredibly important.
Silk is said to have the lowest friction stimulation coefficient (i.e. perception of friction when a fabric is drawn across human skin) of all fiber types.
Smooth to the Skin™
The Interlock Knit Mulberry Silk fabric in Serigena™ Base Layer is Smooth to the Skin™ – it has a smooth, identical surface inside and out (unlike Silk Knit fabrics like Single Jersey, Charmeuse, and others, that have a smooth surface on the outside, and a rougher surface on the inside against the skin). This makes our fabric exceptionally comfortable against the skin and gives it dual side low friction co-efficient (slipperiness). This reduces friction against your skin, and against the mid layer, significantly improving economy of movement.
When you are comfortable and move freely you are ready for optimal performance.
See the performance metrics table below for a direct comparison of our interlock silk fabric ‘slipperiness’, against other base layer fabrics.
Fabric Type | Coefficient of Friction (Dry) | Fabric 'Slipperiness' |
Serigena™ Interlock Silk | 0.15 to 0.25 inside and out | Slides exceptionally well inside & out |
Single Jersey Silk | 0.25 to 0.35 on the inside, 0.15 to 0.25 on the outside | Slides moderatetly well on inside, exceptionally well on outside |
Interlock Merino Wool | 0.25 to 0.40 inside and out | Slides moderately well inside & out |
Silk Weight Polyester | 0.35 to 0.5 | Slides relatively moderately well to poorly, with micro roughness |
Four-Way Stretch Fabric for Optimised Movement™:
The Interlock Silk Fabric Knit we use in Serigena™ Undershirts and Long Pants is considered the gold standard for Baselayer. It is renowned for its four-way stretch, and significant stretch in the width direction, making it very flexible and optimal for movement and exercise.
This maximises freedom of movement, and makes our garments suitable to wear with a snug fit for optimal baselayer function, and for wear under relatively tight fitting outer layers.
Shape Retention & Resilience™
Our Interlock knit fabric has excellent stretch recovery. This helps our garments retain their shape over time. Silk has excellent dry tensile strength and impact resistance. Silk’s strength, suppleness, pliability, & skin compatibility has seen its use in medical sutures for over 4000 years. Quality by design, style by nature™.
Wind Chill Reduction™
The low air permeability of the Interlock Silk fabric we use in Serigena™ Baselayer Under-Garments helps control air movement across the skin in both directions, preserving a warm microclimate of trapped air near the skin, increasing your comfort considerably in cold and windy conditions.
Warm when it Cools – Comfortable when it Warms™
Our Silk Fabric’s high insulation value (or more technically it’s low thermal conductivity), ensures the warmth released by your skin is held close to your body, keeping you warm. Low thermal conductive fabrics are the gold standard for cold weather clothing.
Micro pockets of air trapped within the Silk filaments additionally insulate, reduce radiative heat transmission, and slow the loss of body heat when it is cold.
Our Silk Fabric doesn’t just keep heat in – it’s low thermal conductivity can work the other way and keep external heat out. When temperatures warm, its continuous cycle of moisture absorption from your body and its evaporation to the outside air creates a microclimate of cool, dry air against the skin, keeping you comfortable.
The isothermal properties of silk additionally make the fabric itself feel cool in summer and warm in winter.
Silk has a relatively high moisture regain (MR) of 9 – 11% in the a standardised 65% RH, 20°C test. MR is a measurement of the weight of moisture absorbed by a fiber expressed as a percentage. As relative humidity (RH) increases, silks moisture regain increases with it to around 30% of fabric weight at saturation humidity (100% RH).
Which brings us to another natural advantage of silk. Silk’s high surface area (compared to the surface area of round to elliptical shaped merino wool fibers) attributable to the smooth, triangular cross-section shape of its filaments , enables increased skin to air vapor exchange, facilitating the acceleration of moisture evaporation rates when necessary. This enables heat to be pulled away from the skin by endothermic evaporative cooling. Silk is considered the exemplar natural textile for this effect
Silk’s high infrared emissivity additionally enables our heating body to shed its heat into outer layers and the surrounding air, facilitating passive radiative cooling.
Very high MR fibers like merino wool (MR 9 – 11%), absorb even higher amounts of moisture, especially in high humidity environments. As relative humidity (RH) increases, merino wools moisture regain increases with it to around 33% to 35% of fabric weight at saturation humidity (100% RH). Excessive moisture absorption in wool fabrics in a humid environment makes the fabric heavy and sticky, reduces its breathability, and can cause unpleasant odors. Fabrics with a very high moisture absorption rate will feel colder when exposed to low temperatures due to the formation of ice on and/or in them from the moisture or the acceleration of heat conduction.
Low MR fibers like polyester (MR 0.4%), absorb little moisture but can feel damp and clammy in warm, humid conditions.
Serigena™ Silk Baselayer ability to help you remain comfortable when it warms & provide warmth when it cools makes it The Base Layer to have on hand year-round.
Optimised Skin Microclimate™
Serigena Silk Fabric Baselayer helps buffer your skin moisture levels. The fibroin peptide chain in Silk allows it to absorb up to 30% of its dry weight in moisture before it starts to feel physically damp to the skin. At low to moderate metabolic rates, Silk absorbs perspiration vapor directly into its core, maintaining an optimum near skin microclimate. Excess – liquid perspiration is drawn through tiny gaps between silk filaments via capillary action. It is then moved to the outer surface of the Silk Fabric enabling evaporative cooling.
ECWCS (Extended Cold Weather Clothing System)
Most leisure activities will suit the deployment of just a few clothing layers to suit ambient temperatures and activity level. At the other end of the scale the ECWCS (Extended Cold Weather Clothing System; for extreme environments ranging from +40 °F down to −60 °F / +4°C to −51 °C) developed in the 1980s for the U.S. Army has twelve garment options organised into seven layers. The US Army use silk weight polyester garments at level 1. The ECWCS level 1 principle revolves around wearing a Silk Weight Under Shirt, and Silk Weight Long Pants next to the skin to draw moisture away. We think silk offers the ideal warmth and moisture management system for extended cold weather – and it’s Silk Weight!
The Seven Levels of ECWCS Gen III are:
Level 1: Lightweight undershirt and long pants; wicks moisture away from skin.
Garment 1: Light-weight Undershirt (Silk weight moisture-wicking top)
Garment 2: Light-weight Long Pants (Silk weight moisture-wicking bottoms)
Level 2: Mid-weight grid fleece (‘waffle’) top and bottom; adds warmth.
Level 3: High-loft fleece jacket; serves as primary insulating layer.
Level 4: Wind jacket; lightweight, stretchy, wind-resistant outer shell.
Level 5: Soft shell jacket and trousers; water-repellent and weather-resistant.
Level 6: Extreme wet/cold weather jacket and trousers; waterproof GORE-TEX barrier.
Level 7: Extreme cold weather parka and trousers; PrimaLoft synthetic insulation for static, freezing conditions
More Action – Less Odour™
The Silk Fabric we use in Serigena™ Baselayer is Naturally Antimicrobial and Antifungal. That makes it an unwelcoming environment for the biome that develops during the day with skin perspiration. It enables more action, with less odour. These features also enable the silk fabric to act as a hygienic barrier against exterior contaminants, for superior protection to skin health.
See the performance metrics table below for a direct comparison of our silk base layer fabric odor resistance and drying speed, against other base layer fabrics.
Fabric Type | Odor Resistance | Drying Speed (after washing) |
Serigena™ Interlock Silk | Excellent - silk's natural protein structure repels bacteria | Moderate to fast, up to 2 to 4 hours to air dry |
Interlock Merino Wool | Excellent - merino wool repels bacteria | Slow, up to 12 hours plus to air-dry |
Silk Weight Polyester | Poor - body oils hold to fiber & sustain bacteria | Extremely fast, up to an hour plus to air dry |
Optimisation for Activities from Low to Moderate Intensity Aerobic, up to Moderate to Vigorous Stop, Go, Stop type Activities:
This optimisation of Serigena™ Baselayer makes it exceptionally well suited to Alpine and Downhill Snow Skiing, Snow Boarding, Mountaineering, Travel, Many Adventure and Outdoor Pursuit Activities, Motorcycle Touring & Commuting, Horse Riding, Work Wear, Leisure Wear, and Everyday Wear.
Low to moderate intensity aerobic activities can be technically defined as around 50% to 70% of your maximum heart rate, or approximately 50% to 70% of your VO2 max. To put it more simply, these are activities with an exercise level at which you still have adequate breath capacity to easily converse.
Moderate to vigorous stop, go, stop activities are those where your level of exertion for short periods reaches a point where you can only speak short, broken sentences pausing for breath occasionally, but the activity level often slows or stops enough to regain adequate breath capacity to easily converse.
In these types of activities, our fabric’s ability to thermoregulate and control moisture excels. Select your layers to be worn above it to maximise your comfort as temperatures vary during the day.
During the day wear a mid-layer over the top of the Silk Baselayer to protect it and provide additional insulation. A removable top layer and/or weather shell are complementary to these for your comfort as required.
Flame and Temperature Resistance
100% Natural Silk Fabrics start to dry and shrink when they reach extreme temperatures around 150°C to 230°C. They don’t ignite until they reach around 550°C to 600°C. When ignited Silk does not readily burn and it is self extingushing, and it chars without melting. It has much higher temperature ignition thresholds than cotton (which ignites around 390°C to 400°C), and polyester synthetics (which melt and drip between around 252°C to 292°C).
Silk filament remains structurally stable in Extreme freezing Alpine Temperatures down to -40°C. It retains baseline structural strength down to -18°C. Silk does not ‘cold crack’ and structurally degrade like synthetic polymers at high altitudes.
Crafted by Nature™ Natural & Sustainable
Our Silk is crafted by nature. Its protein profile is remarkably similar to that of the human skin, making it very friendly to your skin. It is a natural, renewable, organic, and biodegradable fiber./ filament. 100% Natural Silk garments are environmentally harmless, breaking down in normal composting soil conditions within 1 to 5 years, leaving no synthetic footprint. The Silk spinning process is almost 90% more energy efficient than processing the polyethylene used in the manufacture of synthetic garments.
Timeless
If the test of time is the yardstick of utility, then the 4700 year history of silk textile speaks volumes to its performance.
