By Oliver Harry - Founder and Creative Director of Ghini Como, a zero-mile silk scarf brand based in Argegno on Lake Como
Quick facts: why silk feels the way it does
- Silk fibre has a triangular cross-section that refracts light at multiple angles, producing the characteristic shifting sheen that also creates the prismatic, cool-then-warm sensation against skin as the fabric moves
- The fibroin protein that forms the structural core of silk has an amino acid composition - approximately 45% glycine, 30% alanine, and 12% serine — that produces a smooth, crystalline surface at the molecular level, which is directly responsible for silk's low friction coefficient against human skin
- Silk's thermal conductivity is approximately 0.04 W/m·K, placing it in a specific range that allows it to feel cool initially on contact and warm quickly to skin temperature - a property that synthetic fibres do not replicate because their polymer chains conduct and retain heat differently
- Silk is naturally hypoallergenic because its fibroin protein is chemically similar to human skin proteins, making it inherently resistant to dust mites, mould, and bacteria without chemical treatment
- The sericin protein that coats raw silk filaments contains amino acids with known moisturising properties, and trace amounts remaining after degumming may contribute to the sensation that silk is gentler against skin than other materials at equivalent thread counts
Why does silk feel so good? The science behind silk's unique properties
Silk is synonymous with smoothness. We often use 'silky' as an adjective, and you could almost say the word is onomatopoeic in its ability to convey the lusciousness of the material.
This grand reputation for luxurious tactility was confirmed when I first held a silk scarf. It's 'silky' smooth without being fragile, a sensation that belies its incredible material strength.
So why does silk feel so good? The answer lies in the protein chemistry and physical geometry of the fibre itself.
The triangular filament and what it does to light and touch
The silk filament produced by Bombyx mori has a triangular cross-section with slightly rounded corners - a geometry that is fundamental to both the optical and tactile properties of the finished fabric.
This triangular profile causes the filament to rest against adjacent filaments and against the skin at an angle rather than lying flat, which produces two distinct effects simultaneously.
Optically, the angled surfaces refract incoming light at multiple angles as the fabric moves, generating the characteristic shifting, prismatic sheen of silk.
This is a quality that satin-weave polyester approximates visually but cannot replicate physically, because polyester filaments have a circular cross-section that reflects light from a single consistent angle rather than refracting it dynamically.
Tactilely, the same triangular geometry means that a woven silk fabric presents a surface to the skin that is composed of angled facets rather than flat planes, reducing the actual contact area between fabric and skin at any given moment.
This is the primary physical reason silk produces less friction against skin than other fabrics at equivalent thread counts - the geometry minimises contact surface, and the molecular smoothness of the fibroin protein does the rest.
The molecular smoothness of fibroin
The amino acid composition of silk fibroin (approximately 45% glycine, 30% alanine, and 12% serine) produces a beta-sheet crystalline structure in which the protein chains are arranged in flat, parallel layers with minimal surface irregularity at the molecular scale.
This crystalline arrangement is what gives silk its tensile strength, and it is also directly responsible for the low friction coefficient of the fibre surface.
Human skin has an average coefficient of kinetic friction against silk of approximately 0.19 to 0.22 under normal contact conditions - measurably lower than against cotton (approximately 0.35), wool (approximately 0.30) and polyester (approximately 0.40), though exact values vary with moisture, pressure, and measurement conditions.
The practical consequence is the specific frictionless sensation that silk produces against skin, the absence of the slight resistance that other fabrics create as they move across the skin surface.
Thermal conductivity and the cool-then-warm sensation
Silk's specific thermal conductivity of approximately 0.04 W/m·K places it in a range that produces a recognisable thermal sequence: initial coolness on contact, followed by rapid warming to skin temperature as the fibre's protein structure absorbs and equalises heat.
This sequence is distinct from the thermal behaviour of synthetic fibres, which retain ambient temperature for longer and do not warm to skin temperature as quickly, producing a more uniform and less responsive thermal sensation.
The initial coolness is real and measurable - it results from the fibre drawing heat away from the skin surface at first contact, in the way that any object with high thermal conductivity relative to the surrounding air will feel cooler than its actual temperature when touched.
The rapid subsequent warming reflects the low thermal mass of the fine filaments, which equilibrate quickly once the initial temperature differential is absorbed.
This combination - cool on contact, rapidly warming and then thermoregulating - is what makes silk comfortable against skin across a wider temperature range than most fibres, and it cannot be replicated by blended or synthetic fabrics because it depends on the specific protein chemistry of fibroin rather than on weave structure or thread count alone.
Hypoallergenic properties: what the chemistry actually means
Silk's frequent description as hypoallergenic reflects a specific and verifiable property of fibroin: its chemical similarity to the keratin proteins found in human skin and hair means it does not trigger the immune responses that synthetic polymer fibres and even some plant fibres can provoke in sensitive skin.
Fibroin does not contain the irritant compounds present in wool (lanolin, in sensitive individuals), the chemical finishes often applied to cotton, or the static charge that polyester generates from friction.
Additionally, silk's smooth surface and low moisture retention relative to cotton and linen create an inhospitable environment for dust mites, which require humid, textured environments to colonise a fabric.
This property is structural rather than chemical and persists through repeated washing without any specialist treatment.
Oliver Harry is the founder and creative director of Ghini Como, a luxury silk scarf brand which uses silk sourced entirely from the Province of Como, Italy. He lives in Argegno on the western shore of Lake Como.
