A guide to cover fabrics — from poplin to alpaca
Bedding descriptions in shops mix up two completely different things: weave and fibre. “Cotton sateen” is a satin weave made from cotton. “Satin” without an adjective may well mean polyester. “Bamboo” almost always means viscose produced from bamboo cellulose, which is a chemically regenerated fibre. Until you separate those two axes, comparing offers is pointless.
This is a guide to the whole category, not to our own collection. At the end we say what we choose and why, but first — how any of it works.
Axis one: the weave
The weave decides how a fabric drapes, how it catches light, and how much air it holds.
| Weave | Construction | To the touch | Who it suits |
|---|---|---|---|
| Plain (poplin, percale) | One under, one over — the simplest possible interlacing | Cool, slightly crisp, matte | People who overheat |
| Satin / sateen | A warp thread passes over four or more weft threads | Smooth, heavy in the drape, with a sheen | Those who like cool smoothness and drape |
| Waffle | A three-dimensional grid of recesses | Dry, springy, airy | Night sweaters; fast drying |
| Knit (jersey) | Loops, not interlacing — the fabric stretches | Soft, warm, clinging | Cold bedrooms, children |
| Flannel | Plain or twill weave with a brushed surface | Fuzzy, insulating | Very cold rooms |
| Crepe, crinkled satin | A weave with a finish that crimps the surface | Soft, irregular, matte-to-lustrous | Those who do not iron and do not plan to start |
Poplin and percale share the same plain weave; the difference lies in thread thickness. Percale uses threads of equal thickness in both directions, poplin usually a slightly thicker weft, giving a barely visible rib. In practice both produce the same result: a cool, dense fabric that softens at the first wash and stops rustling.
Satin has long thread floats on the surface — hence the sheen and the smoothness. The price is lower snag resistance: satin pulls more readily against a fingernail or a buckle. Cotton satin is often confused with polyester satin, which looks similar in a photograph and behaves completely differently at night.
Waffle is the weave that builds the most volume from the same quantity of cotton. The pockets hold air but also exchange it very quickly, so the fabric does not accumulate moisture. It is the best choice for people who wake up damp — and the worst for anyone looking for a smooth surface.
Axis two: the fibre
Here one number explains most bedding experiences: moisture regain — how much water a fibre takes up under standard conditions, expressed as a percentage of its own mass.
| Fibre | Moisture regain | Character | Note |
|---|---|---|---|
| Cotton | approx. 8.5% | Universal, softens with every wash | Creases; long-staple (Egyptian, Pima) pills less |
| Linen | approx. 12% | Cool, better every year | Expensive, visibly creased — a feature, not a fault |
| Viscose (incl. bamboo) | approx. 13% | Very smooth, cool to the touch | Loses strength when wet; a chemical fibre, not a plant one |
| Lyocell / Tencel | approx. 11.5% | Smooth, more durable than viscose | Made in a closed-loop solvent process |
| Wool, alpaca | approx. 15–17% | Warms even when slightly damp | Rare in covers; as duvet filling — yes |
| Polyester, microfibre | below 0.5% | Cheap, crease-free, dries fast | Moisture stays on the skin — hence clammy heat near dawn |
A few things worth holding in mind when reading labels:
- Bamboo is viscose. The fibre is produced by chemically dissolving cellulose. It can be very pleasant, but describing it as natural is a stretch, and claims about bamboo's antibacterial properties do not carry over to the finished viscose.
- Microfibre is polyester with a very fine filament. It can be soft and it is cheap, but that does not change its moisture regain.
- Minky, plush, coral fleece — children's fabrics with a lovely hand, nearly always polyester. For a child who overheats they are the worst possible choice.
- 50/50 blends behave closer to polyester than to cotton, despite the proportions on the label.
The thread count myth
Threads per inch is the most abused figure in the whole industry. Physically only so many single-ply threads fit into an inch — above roughly 400, the increase is largely achieved by counting multi-ply threads as separate ones. That is where 1000 TC labels on fabric thinner than a decent 200-count percale come from.
A more honest parameter is fabric weight, in grams per square metre. For cotton bedding the sensible range is 110–150 g/m² for poplin and percale, 120–160 for satin, 180–220 for flannel and linen. If a shop publishes the weight, it usually means there is nothing to hide.
Certificates — what each one means
- OEKO-TEX STANDARD 100 — testing of the finished article for harmful substances. It says nothing about the origin of the raw material or production conditions, but it does say the fabric touching skin has been tested. Children's bedding falls under the strictest class I.
- GOTS — covers fibre origin (minimum 95 percent certified organic cotton for the organic grade) and the entire processing chain, including social criteria.
- OEKO-TEX STeP — applies to the production facility, not the product.
- Hypoallergenic — not a certificate and not regulated in any way. The real mechanism limiting dust mites is a dense plain weave acting as a barrier, not a claim on a label.
What this means for a weighted blanket
In a weighted blanket the cover has one job more than ordinary bedding: it has to move moisture through a thicker-than-usual layer of filling. Underneath sits a non-woven layer with microbeads, which is itself a barrier. Put a polyester cover on top of that and the vapour has nowhere to go — hence the familiar overheated feeling near dawn, in a cool room.
The second point is attachment. A weighted blanket weighs six to twelve kilograms, and if it slides inside the cover the mass gathers in one corner. The cover needs a zip along the whole short edge and corner ties. This is the detail you discover at the third wash.
The third is washing. A cotton cover comes off and goes into a 40-degree wash; the weighted blanket itself usually will not fit a domestic machine because of the mass of wet filling. That is why a spare cover is not a luxury but the condition for the blanket lasting several years.
Which weave for whom — the short version
| If you… | Choose | Avoid |
|---|---|---|
| wake up overheated | waffle, percale, linen | flannel, microfibre, minky |
| get cold at night | flannel, cotton jersey | linen, waffle |
| want smoothness and drape | cotton satin, lyocell | waffle, linen |
| do not iron | crinkled satin, crepe, linen | smooth poplin, smooth satin |
| are buying for a child | cotton in OEKO-TEX class I | minky and plush for a child who sweats |
| are allergic to dust mites | dense percale as a barrier, 60°C washing | fabrics that require a 30°C wash |
Frequently asked questions
Is satin warmer than poplin?
At the same fabric weight the difference in insulation is small, but satin feels warmer because its smooth surface sits closer to the skin and reduces air movement right at the body. Poplin reads as cooler for the same reason.
How often should bedding be washed?
Every seven to ten days in normal use, more often in summer and with dust mite allergy. Washing at 60°C effectively limits mites but shortens fabric life — a good compromise is 40°C with one 60°C cycle a month.
Why does new bedding rustle?
Because of factory finishing agents and residual starch. After a first 40-degree wash with half the usual detergent and no fabric softener, it softens. Softener reduces cotton's absorbency over time, so it is better skipped.
Does a weighted blanket cover have to be the same brand?
No, but the dimensions must match to the centimetre and the cover must have ties. A blanket floating loose in an oversized cover gathers filling in one corner and loses even pressure — which is precisely what you bought it for.
Summary
The weave decides the hand and how much air the fabric holds; the fibre decides what happens to moisture. Cotton takes up around 8.5 percent of its own mass in water, polyester under 0.5 — and that is the whole difference between a settled night and a clammy 3 am. Thread count is a marketing number; fabric weight is more honest. For a weighted blanket the cover additionally needs a zip and ties, and a spare one is the condition for the blanket lasting.
Sources
- Fibre moisture regain values — textile standards ASTM D1909 and fibre producers' data
- OEKO-TEX STANDARD 100 and GOTS — public certification criteria, versions in force in 2026
- Okamoto-Mizuno K., Mizuno K., “Effects of thermal environment on sleep and circadian rhythm”, Journal of Physiological Anthropology 2012;31:14 — bed climate data
See also
- Aura — crinkled satin Washed satin, unironed by design
- Duvet covers A spare cover for rotation
- Family in a waffle cover The weave with the most trapped air
Crinkled satin — a satin weave with no ironing obligation
The Aura line is made from cotton satin with a crinkled finish: the smooth face of a satin weave, but a structure designed not to need an iron. Three colours — Night Navy, Saffron Mustard, Morning Mist — in adult and children's sizes. Until 31 October the entire Aura line is 20% off, and Single, Family in poplin and Kids Comfort are 25% off. Sewn in Poland. Courier or InPost parcel locker delivery, 14 days to return, free weight exchange within that period.
This article is informational and concerns sleep comfort and general wellbeing. A weighted blanket is not a medical device and does not replace consultation with a specialist.