The Complete Guide to Silk
The short answer
Silk works on hair and skin for one reason above all others: it creates far less friction than cotton. Everything else follows from that.
The terms you meet when shopping fall into two groups. Some describe the silk and are worth understanding. Most of the rest are marketing.
Momme, explained properly
Momme (written mm, pronounced mo mee) is a weight measurement. It is the weight in pounds of a piece of silk 100 yards long and 45 inches wide.
This is where most silk buying guides mislead people. Momme is routinely presented as a quality ladder where higher is better. It is not. Momme tells you how heavy and dense the fabric is, not how good the silk is. A poorly graded silk at 25 momme is still poorly graded silk.
| Momme | Character | Suits |
|---|---|---|
| 16 to 19 | Lighter, more breathable, more fluid drape | Warm climates, anyone who sleeps hot, people who dislike a heavy fabric against the face |
| 22 to 25 | Denser and heavier, warmer against the skin | Cooler climates, anyone who prefers a substantial fabric |
| 30 | Very heavy | Specialist use, rarely necessary |
It is a trade off rather than a ranking. Heavier silk is more robust but sleeps warmer and costs more. Lighter silk breathes better and feels weightless on the face. For anyone who runs warm at night, a lighter weight is often the better experience rather than the compromise.
White Lotus pillowcases are 19 momme mulberry silk, chosen for breathability and a light feel against the skin. The sports cap is lined with 19 momme pure silk rather than mulberry silk, which is a different specification and one we state accurately rather than borrowing the category's default language.
What matters more than momme is what comes next.
Grade is the quality measure
Mulberry silk is graded from 6A down through 5A, 4A and lower. The grade reflects fibre length and consistency, which is what actually determines smoothness and durability.
A product that states its momme but not its grade is telling you about weight while staying quiet about quality. That is the specification to ask about.
Mulberry silk versus silk
All mulberry silk is silk. Not all silk is mulberry silk.
Mulberry silk comes from the Bombyx mori silkworm, fed exclusively on mulberry leaves. That controlled diet produces long, uniform, round fibres. Long fibres mean a smoother finished surface with fewer joins, which means less friction.
Wild or tussah silk comes from moths feeding on varied leaves. Shorter, coarser, more irregular. Still silk. Not as smooth.
Across the White Lotus range, the pillowcases, eye masks and scrunchies are mulberry silk. The sports cap is lined with pure silk. All of it is peace silk. We separate those two claims because most of this category uses mulberry as a generic word for silk whether it is accurate or not.
Peace silk, and why it changes things
This is the distinction almost nobody in the category runs, because almost nobody can.
Conventional silk production boils the cocoon with the moth still inside, because an intact cocoon yields a single unbroken filament. Peace silk, also called ahimsa silk, allows the moth to emerge before the cocoon is processed. Ahimsa translates as non violent.
The entire White Lotus silk range is peace silk. The worms are not killed in harvesting and go on to become moths and continue the cycle.
There is a practical consequence worth knowing. Because the moth breaks the cocoon on its way out, the filaments are shorter and are spun rather than reeled as one continuous thread. Peace silk therefore rewards gentle washing slightly more than conventional silk does.
Peace silk is still an animal fibre and we do not describe it as vegan. White Lotus is PETA certified cruelty free.
Charmeuse weave
Charmeuse is a weave, not a fibre. It produces one lustrous face and one matte back, and the lustrous side is the one that should touch your hair and skin.
The sericin question, honestly
You will read that silk is naturally antibacterial and antifungal because of sericin, the protein binding the fibres in the raw cocoon.
Here is the part those claims leave out. Sericin is largely removed during degumming, the standard processing step that gives silk its softness and drape. A finished, soft silk pillowcase contains very little sericin. Claims built on sericin content in a degummed product are overstated across most of this category.
We would rather tell you that than repeat it.
What the evidence actually supports
The friction argument is the strong one, and it is mechanical rather than clinical. A smoother surface means hair moves across the fabric rather than catching on it, so there is less breakage, less frizz and fewer tangles in the morning. This is measurable and it is why silk earns its place.
Silk is also less absorbent than cotton, so it draws less moisture from hair, skin and anything applied before bed.
Where the evidence thins is on skin. The claim that a silk pillowcase reduces facial wrinkles is repeated constantly and the published research behind it is limited and mostly small in scale. It is reasonable to say that reducing overnight friction and compression on the face is unlikely to hurt and may help. It is not reasonable to present it as an established anti ageing result, and we will not.
We are qualified acupuncturists and we have sold silk since 2004. We would still rather understate this than oversell it.
Day and night: which product does what
The three products cover different windows. They are complements rather than alternatives.
| Product | When | Protects against |
|---|---|---|
| Silk pillowcase | Overnight | Friction from the sleeping surface, plus contact with facial skin |
| Silk lined cap | Daytime | Sun, wind, and friction from the lining of the covering itself |
| Silk eye mask | Overnight, travel and relaxation | Light, and creasing around the eye area |
The pillowcase is the lowest effort change available. You make the bed once and it works every night. It is also the only one of the three doing meaningful work for facial skin.
The cap is daytime wear. Most hats are lined with cotton, wool or synthetic fabric, all of which catch and pull, so a hat worn to protect hair can abrade it instead. A silk lining means the covering protects rather than damages. If you have ever taken off a beanie and found hair on the lining, that is the problem it solves.
The eye mask works on the thinnest skin on the face and blocks light. It is also the most useful of the three for travel, where you have no say over the pillow you are given.
Most people start with the pillowcase. Pillowcase and cap together is the complete version, covering the full twenty four hours.
Browse the silk pillowcase collection, the silk lined hats collection, the silk eye mask collection, or the full silk collection.
Care in one paragraph
Wash silk by hand or on a delicate cycle in cool water using a detergent made for silk or wool. Never bleach and never enzyme or biological detergent, since protease enzymes digest protein and silk is a protein fibre. Never tumble dry. Never wring. Press between a towel and dry flat away from direct sun and heat.
Frequently asked questions
What does momme mean on a silk pillowcase?
Momme measures the weight and density of the fabric, not its quality. Lighter weights breathe better and feel weightless. Heavier weights feel denser and sleep warmer. Grade is the measure of quality.
Is higher momme always better?
No. Momme is a trade off, not a ranking. Heavier silk is more substantial but warmer and more expensive. Lighter silk breathes better, which suits warm climates and anyone who sleeps hot.
What is peace silk?
Peace silk, or ahimsa silk, allows the moth to leave the cocoon before processing rather than the cocoon being boiled with the moth inside. The entire White Lotus silk range is peace silk.
Is silk vegan?
No. Silk is an animal fibre, including peace silk. Peace silk changes the welfare question rather than the fibre question. White Lotus is PETA certified cruelty free.
Is a silk pillowcase better for your hair?
The friction argument is the well supported one. Silk is far smoother than cotton, so hair slides rather than catches, which reduces breakage, frizz and tangles overnight.
Do silk pillowcases prevent wrinkles?
The published research is limited and mostly small scale. Reducing overnight friction and compression on facial skin is unlikely to hurt, but it should not be presented as an established anti ageing result.
Is a silk lined cap worn at night?
No, it is daytime wear. Overnight protection comes from the silk pillowcase. The cap protects against sun, wind and friction from the lining of the covering itself.
How do you wash silk?
Hand wash or use a delicate cycle in cool water with a silk or wool detergent. No bleach, no enzyme detergent, no tumble dryer. Dry flat away from direct heat and sun.