Know your fibers
Silk
Silk is a protein fiber, chemically closer to your own hair than to any plant. It is the strongest natural fiber by weight, it is thermoregulating in both directions, and its triangular cross-section is what produces the lustre nothing else replicates.
It is also the fiber most routinely imitated. Polyester satin is engineered specifically to look like silk in a photograph, and at the price points where imitation is most common it is very hard to tell from a product image.
- Blouse weight
- 12 to 16 momme
- Substantial
- 19 to 22 momme
- Weakness
- Water marks, sun
Momme, the number that matters
- Momme (mm) is silk’s weight measure. 12 to 16 is standard for blouses. 19 to 22 is substantial, the weight used for good bedding and heavier shirting. 25 and above is dense and rare.
- Charmeuse, satin weave, lustrous face and matte back. The classic slip dress.
- Crepe de chine, matte with a slight grain. Drapes beautifully and shows water marks less.
- Habotai, lightweight and plain. Often used for linings and the cheapest silk garments.
- Mulberry silk means the Bombyx mori worm fed on mulberry, the standard for long uniform filaments. Wild and Tussah silks are shorter and more textured by nature.
If a satin dress is priced like polyester, it is polyester. Silk at that weight has a floor.
Spotting the substitute
Real silk warms quickly in the hand and has an uneven, deep lustre that shifts colour as it moves. Polyester satin stays cool, shines evenly, and tends to a plasticky slide. The composition line settles it faster than either test.
Care, which decides how long it lasts
- Hand wash cool with a pH-neutral or dedicated silk wash, or dry clean. Never bleach.
- Do not wring. Roll in a towel and press, then dry flat away from direct sun.
- Iron on the reverse, low, slightly damp. Direct heat scorches protein fiber permanently.
- Keep perfume and deodorant off it. Alcohol and aluminium salts degrade the fiber and leave marks that do not come out.
- Store out of light. Sunlight yellows and weakens silk faster than wear does.
The honest trade-offs
Water-spots, degrades in sunlight, weakens from perspiration, and generally cannot be machine washed. It is a material that asks something of you.