This is the question I get most, and it almost always arrives the same way. Someone has finally decided she is done sleeping in polyester. She is ready. And then she gets to the part where she has to choose, and she stalls.
I understand the stall. It feels like a test you could fail. You are about to spend real money on something you will wear more hours than anything else you own, and you do not want to get it wrong.
So let me take the pressure off.
There is no better one. Silk and organic cotton are not competing for the same job. They are two different answers to two different kinds of nights, and the right one for you depends almost entirely on how you actually sleep. Not how you wish you slept. How you actually do.
Here is how to tell which one is yours.
What silk is quietly very good at
Silk is a protein fiber. It is closer in structure to your own hair and skin than any plant fiber is, and that is the whole reason it behaves the way it does against your body.
It runs cool. This is the first thing people notice and it is not in their heads. Silk is light, it does not insulate the way a heavy knit does, and it pulls heat off your skin the moment it touches you. If you are someone who kicks a leg out from under the duvet at 2am, silk is built for exactly that night.
It does not grab. This is the one people underestimate until they feel it. Cotton has texture, and texture creates friction. Over eight hours of turning, that friction tugs at your hair and drags on your face. Silk has almost none of it. You wake up with less of a crease on your cheek and less of a nest in your hair.
It is light without being thin. Our nightgown is woven at 19 momme, so it stays airy and cool. The robe is 22 momme, which gives it that heavier liquid drape, the kind that actually falls instead of floating.
Silk is for you if: you run warm, you wake up overheated, you care about your hair and your skin, you want to feel beautiful in it, and you want something that feels like an occasion on an ordinary Tuesday.
What organic cotton is quietly very good at
Cotton gets treated like the practical choice, as if practical means lesser. It is not lesser. It is just honest about what it is.
It keeps you warm. Let me be straight about this, because the internet gets it wrong constantly. Cotton is the warmer fabric. It is thicker than silk, a top and a pant cover nearly all of you where a nightgown leaves your arms and legs out, and cotton holds onto warmth rather than letting it go. The idea that cotton is the cool choice comes from comparing it to polyester, not to silk.
That is not a flaw. That is the whole point of it. There are nights when you want to be wrapped up, and a cold bedroom in January is not a problem silk was built to solve.
And warmer than silk is not the same as hot. Next to polyester, cotton is a different world. Polyester traps heat and holds moisture right against your skin, because plastic has nowhere to put it. Cotton breathes, and more importantly, cotton absorbs.
That matters enormously if you wake up sweating. If you are in the years where you go to bed fine and wake at 3am soaked, you already know that the worst part is lying there in something clammy that will not dry. Cotton pulls that moisture off your skin and takes it into the fiber. Polyester just moves it around. It is the difference between a towel and a raincoat.
It covers you. A nightgown is lovely and it is also a nightgown. Some nights you want sleeves and you want pants. You want to answer the door for a package, make coffee, sit with your laptop, and not feel like you are in lingerie. A button-up top and a drapey pant is a different kind of comfort.
It gets better. This is cotton's real gift. Silk arrives at its best and you protect it. Cotton starts good and softens every single time you wash it. In two years your cotton set will be the softest thing you own, specifically because you have worn it to death.
And it goes in the machine. Cold, gentle, done.
Cotton is for you if: you get cold at night, you wake up sweating and want something absorbent against your skin, you want to be covered, you want something you can wash without thinking about it, and you want a pajama that feels like a well-loved sweatshirt instead of an event.
The honest way to choose
Forget fabric for a second and answer three questions.
Do you want to be covered or uncovered? If the answer is covered, you want the cotton set. No amount of silk's loveliness fixes the fact that a nightgown is not a pajama set.
Do you wake up too hot, or do you go to bed cold? Too hot is silk, every time. Cold is cotton. If you are the person who sleeps in socks, you are a cotton person and you always were.
Do you want to care for it, or not think about it? Silk asks a little of you. Cold water, a mesh bag, no bleach, hang to dry. It is five extra minutes a month and it will last you a decade. If those five minutes will genuinely annoy you, that is useful information. Buy the cotton.
If your answers split down the middle, start with whichever one matches the night you have most often. You are not marrying it.
The part that matters more than either answer
Here is what I actually want you to take from this.
The difference between silk and organic cotton is a difference of preference. The difference between either of them and polyester is a difference of kind.
Polyester is plastic. It does not breathe, it traps heat and moisture against you, and it is finished with a list of chemistry that nobody prints anywhere you can read it. You spend roughly a third of your life in sleepwear, with the fabric warm and pressed against skin for eight hours straight. That is more sustained contact than almost anything else you put on your body.
So the real decision was the one you already made, the moment you decided you were done with plastic. Silk or cotton is just picking your favorite way to be done with it.
What stays the same either way
Whichever you choose, the standard underneath it does not move.
Our silk is 100% pure mulberry silk, grade 6A, certified to OEKO-TEX Standard 100. That certification tests against a list of hundreds of restricted substances. No formaldehyde. No toxic azo dyes. No heavy metals. It is held to the strictest product class, the one written for what babies wear.
Our cotton is made with GOTS-certified organic cotton and colored with azo-free dyes, made through fair trade manufacturing by people paid fairly and working in safe conditions.
Both are natural fiber. Neither is plastic. Neither has elastane hiding in the blend.
That is the floor. Everything above it is just about which one suits your nights.
So, which one?
If you want my honest read: most women should start with whichever one answers the question they actually have.
If the thought that made you start looking was I keep waking up hot and I think my pajamas are the problem, start with silk.
If the thought was I am always cold, I want to be covered, and I want to stop worrying about what this stuff is made of, start with cotton.
And if the thought was I just want to feel beautiful going to bed, you already know. It is the silk. You were only waiting for permission.
Our Silk Nightgown and Silk Robe are available now, and the Organic Cotton Pajama Set arrives this November in Cloud Blue and Cloud Pink. If you want to know the day it lands, join the Early Access Circle and I will tell you first.
By Ann Havenly
MoonThreads silk is certified to OEKO-TEX Standard 100. Our cotton is made with GOTS-certified organic cotton and produced through fair trade manufacturing.