The Silk Guide
What is silk?
Silk is a natural protein fibre produced by the Bombyx mori silkworm. The worm spins a cocoon from a single continuous thread — up to a kilometre long — made from a protein called fibroin. Those threads are unwound, spun together, and woven into fabric.
Mulberry silk — the type used in quality sleepwear — comes from silkworms fed exclusively on mulberry leaves. It's the highest grade of commercially available silk, prized for its fineness, strength, and natural sheen.
What does "momme" mean?
Momme (written as "mm") is the standard density measure for silk — how much silk is woven into a square metre of fabric. The higher the momme, the heavier and more durable the fabric.
As a guide:
- Under 12 momme — Very lightweight and delicate. Prone to snagging. Not suitable for everyday sleepwear.
- 12–16 momme — Lightweight. Fine for scarves and linings.
- 19–22 momme — The sweet spot for sleepwear. Substantial enough to drape beautifully and last for years. Light enough to sleep in comfortably.
- Above 25 momme — Heavier weight. Starts to feel like formal fabric rather than sleepwear.
All & moon silk slips are made at 19 momme — right in the ideal range for sleepwear.
What is crepe satin?
Crepe satin is a specific weave used in silk fabric. It combines the fluid drape and soft sheen of a satin weave with a slightly more textured surface than standard charmeuse. The result is a fabric that looks refined rather than glossy — more wearable, less costume-like.
The & moon silk slips are made in a crepe satin weave. It photographs beautifully without looking synthetic, and the subtle texture makes it look intentional rather than shiny.
What is the difference between silk and satin?
Silk is a fibre. Satin is a weave. These are different things.
You can make a satin weave from silk threads, polyester threads, or anything else. "Silk satin" means silk fabric woven in a satin pattern. "Satin" on its own — with no fibre content listed — almost always means polyester.
When you're buying anything labelled satin, check the fibre content on the label. "100% silk" or "100% mulberry silk" is what you're looking for. "Satin," "silky satin," "silk-feel," or "charmeuse" without a fibre content listed means the fabric is likely synthetic.
How do I know if something is real silk?
Four ways to check:
1. Read the label. A genuine silk garment must by law list its fibre content. Look for "100% silk" or "100% mulberry silk." If it just says "satin" or "silk-feel," it isn't silk.
2. Check the price. Real silk costs what it costs to produce. Genuine silk sleepwear doesn't retail below ~$60–70 AUD. If the price seems implausibly low for silk, read the label carefully.
3. The touch test. Silk warms to body temperature almost immediately. Hold it against your inner wrist — within a few seconds it should feel like part of your skin, not a separate cool or slightly sticky material. Polyester satin has a slightly artificial slipperiness and takes longer to warm up.
4. The burn test. This is definitive. Pull a single thread from an inside seam and hold it to a flame. Silk burns slowly, self-extinguishes when removed from the flame, and leaves a fine crushable ash. It smells like singed hair — because the protein structure is similar. Polyester melts rather than burns, smells synthetic and acrid, and leaves a hard plastic bead that you can't crush between your fingers.
Why is silk good for sleep?
Three reasons that are backed by the properties of the fibre — not marketing language.
1. Moisture retention. Silk doesn't absorb moisture from your skin the way cotton does. Cotton draws moisture from wherever it can find it — including your face. Silk's natural protein structure is more compatible with skin, which means your skin retains more of its natural moisture overnight. This is particularly relevant if you use serums or moisturisers at night — cotton absorbs them; silk doesn't.
2. Hair friction. Silk creates almost no friction against hair fibres. Cotton and polyester are rough at a fibre level, and that roughness causes the mechanical stress on your hair while you move in your sleep — leading to frizz, breakage, and the particular kind of morning-hair that takes twenty minutes to undo. A silk slip and silk pillowcase used together significantly reduce this.
3. Temperature regulation. Silk breathes — it allows air to circulate — but it also has a mild natural insulating quality. This means it adjusts to your body temperature rather than working against it. If you run hot at night, silk is cooler than polyester (which traps heat). If you get cold, it has more warmth than a thin cotton slip. It adjusts to you.
How do I care for silk?
Silk is more durable than people expect, but it does require a little care.
Washing:
- Hand wash in cool water with a pH-neutral or silk-specific detergent
- Or machine wash on the delicate/gentle cycle inside a mesh laundry bag
- Use cool water — never hot
- Don't wring or scrub
Drying:
- Roll in a clean towel to absorb excess water — don't wring
- Lay flat or hang to air dry
- Keep away from direct sunlight — prolonged UV exposure weakens silk fibres and can cause colour fading
- Never tumble dry
Ironing:
- Iron on the lowest silk setting if needed
- Always place a cloth between the iron and the silk
- Iron while slightly damp or use a steam iron from a distance
- Never iron dry silk directly
Storage:
- Store hanging or loosely folded
- Avoid plastic bags — silk needs to breathe
- Keep away from direct sunlight and heat sources
- For white silk specifically: wrap in blue tissue paper to prevent yellowing over time
Does silk wrinkle?
Yes — silk wrinkles. This is normal and expected for a natural fibre. Crepe satin wrinkles less than some other silk weaves because the textured surface disguises minor creases. Most wrinkles fall out naturally when you wear the garment — the warmth of your body relaxes the fabric. For more stubborn wrinkles, a light steam from a distance is enough.
How long does silk last?
A well-cared-for silk garment can last many years — far longer than synthetic alternatives, which degrade faster with washing. Silk doesn't pill (pilling is a synthetic fabric problem). The colour may soften very slightly over years of careful washing, which is normal for natural fibres.
The main things that shorten silk's life: hot water, tumble drying, harsh detergents, direct sunlight, and rough handling. Avoid those and silk is remarkably durable.
Is silk sustainable?
Silk is a natural protein fibre — it biodegrades at the end of its life, unlike polyester which takes around 200 years to break down and sheds microplastics with every wash.
Silk production does require significant water and energy, and the sericulture process (silkworm farming) has its own environmental considerations. It isn't perfect. But compared to synthetic "luxury" alternatives — most of which are polyester — real silk is significantly more sustainable as a long-lived, biodegradable natural fibre.
The most sustainable approach with any garment is to buy less and buy better. A silk slip cared for properly and worn for years is a different environmental proposition to a synthetic slip replaced every season.
& moon makes 100% Vietnamese mulberry silk slips designed in Australia. If you have a question not answered here, contact us at info@andmoon.com.au