Quasso Insights · Materials & Fabrics
What you don’t know about
silk
even though you wear it often
A fiber with a unique physical structure and a surprising history, hidden behind a material we take for granted.
Silk is arguably the material most associated with luxury—and yet the least understood. We know it shines, it feels cool on the skin, and it is expensive. We rarely know why.
The answer has less to do with marketing and more to do with the chemistry of a fiber produced by a caterpillar, structured in a way that no synthetic material has been able to fully replicate, and a history of weight fraud that lasted nearly a century.
Raw fiber is not yet true silk
The silk thread, as it emerges from the worm's cocoon, is covered in a natural "glue" called sericin—a protein that binds the fibers together and protects them during the cocoon's formation.
Reference study — Composition and removal of sericin
Research on the silk degumming process (Bombyx mori)
Sericin represents approximately 25-30% of the raw silk's weight. The degumming process—boiling the fiber in alkaline or enzymatic solutions—removes this layer and exposes fibroin, the protein responsible for silk's characteristic luster and softness. Incomplete degumming leaves the silk stiff, matte, and prone to a slight squeaking sensation when touched.
TEXTILE RESEARCH — SILK DEGUMMING PROCESS
Basically, low-quality silk isn't necessarily "fake silk"—it could be real silk, but incompletely processed. The test is simple: well-degummed silk slides smoothly between your fingers; poorly processed silk squeaks slightly and feels somewhat stiff.
Heavy silk is not necessarily good silk
For nearly a century, the silk industry practiced something few people know about today: "loading" the fiber with metal salts, especially tin, to increase its weight.
Reference study — Historical "silk loading" practice
Historical documentation on metallic salt "weighting" processes (19th-20th centuries)
Silk was traditionally sold by weight, and the degumming process removed about one-fifth of the raw fiber's weight. Starting in the latter part of the 19th century, producers began to compensate for this loss—and often far exceed the original weight—by treating the fibers with tin salts, sometimes reaching an increase of up to ten times the initial weight. In 1938, the U.S. Federal Trade Commission mandated the "Weighted Silk" label for fabrics that exceeded a certain loading threshold.
HISTORY OF TEXTILE REGULATIONS — USA, 1938
The irony of the practice: while metallic salts created a heavier fabric with a more dramatic drape, they significantly accelerated the fiber's degradation—many "loaded" historical pieces break and crumble today much faster than silk not processed in this way. Weight, in isolation, has never been a correct indicator of quality.
The luster no synthetic can copy
Under a microscope, a degummed silk thread has an unusual shape: a triangular cross-section with slightly rounded corners—basically a tiny natural prism.
Reference study — Optical structure of silk fiber
Analysis of fiber structure and optical properties of silk
The triangular shape of the silk fiber causes light to be refracted and reflected at multiple angles, rather than reflected uniformly like a circular cross-section fiber. This phenomenon produces the multi-faceted, shimmering luster characteristic of silk. Synthetic fibers, usually extruded with a circular section, reflect light in a much more uniform and flat way—which is why they cannot fully reproduce the natural luster of silk, regardless of the thread's fineness.
FIBER STRUCTURE — TRIANGULAR CROSS-SECTION
This is the difference between "silk" and "silk-like"—it's not about how smooth the thread seems at first glance, but about a microscopic geometry that the synthetic industry has yet to faithfully reproduce.
The enemy: direct light
Silk is one of the most sensitive natural fibers to ultraviolet light—far more sensitive than cotton or wool, for example.
Reference study — Photodegradation of silk fibroin
Effects of ultraviolet radiation on silk fibroin
Exposure to UV radiation triggers photo-oxidation reactions in the protein structure of the silk, forming new chemical compounds that shift its color toward yellow and reduce the fiber's crystallinity. This process weakens the fiber structure at the molecular level, making it more brittle and prone to tearing, even if the damage is not immediately visible on the surface.
STUDIES ON FIBROUS PROTEIN PHOTODEGRADATION
Basically, a silk dress or shirt left to dry in direct sunlight or stored for years near a sunny window will deteriorate much faster than one kept in the shade—even if the difference is not immediately visible to the naked eye.
What to remember about silk
- ◆Silk that squeaks or feels stiff was likely incompletely degummed; it is not necessarily "fake."
- ◆Weight alone does not guarantee quality—historically, it was often a sign of manipulation, not value.
- ◆Natural luster comes from a physical structure (the triangular section), not just thread fineness.
- ◆Dry and store silk away from direct light—UV light weakens it from within, it doesn't just bleach it.
"The silk you wear today has a worm behind it, a chemical process of centuries of controversy, and a microscopic geometry that science has only just managed to fully explain."
Quasso Insights · Materials & Fabrics
