BEDDING GUIDE · 20 OCTOBER 2026 · BY LAVE STUDIO

How to choose a duvet: filling, warmth and size

The best duvet for you is the one that suits your room, your sleeping temperature and the care you can realistically give it. Start there before choosing a filling or a brand.

1. Start with the bedroom you actually sleep in

Notice how your room feels at bedtime and in the morning. Does the heating switch off overnight? Is it a warm flat or a cooler spare room? Do you regularly push the duvet away? These observations are more useful than choosing a product simply because it is labelled “winter”.

If two people share a bed but sleep at different temperatures, consider separate inserts or a lighter duvet with an extra layer for the colder sleeper.

2. Compare the feel and care, as well as warmth

Filling	What to consider
Silk	A close, low-profile drape. A useful option if you dislike puffy bedding. Check the insert’s cleaning instructions before buying.
Down and feather	Consider if you prefer loft. Check the down/feather composition, tested warmth information and care label.
Wool	Compare the finished duvet’s weight, drape and cleaning requirements. Construction varies between products.
Synthetic	Worth comparing where frequent washing is a priority. Check the permitted wash temperature and whether your machine has enough capacity.

No filling name alone tells you how warm, washable or comfortable a particular duvet will be. Independent Consumer Council duvet testing assesses finished products for this reason; those results are not tests of Lave’s insert.

3. Understand TOG and filling weight

TOG describes thermal resistance. Grams per square metre describe the amount of filling over a given area. They are different measurements: 250 g/m² cannot be converted into a reliable TOG value without testing the finished duvet.

Lave offers 150, 250 and 400 g/m² silk fills. Within our range, more silk means more insulation. The labels Light, Medium and Warm are a starting point, not a promise of a particular sleeping temperature.

For worked examples, read our guide to silk duvet fill weights.

4. Match the cover, not just the mattress name

Check the width and length on your removable duvet cover. Lave’s standard options are Single 135 × 200 cm, Double 200 × 200 cm, King 225 × 220 cm and Super King 260 × 220 cm. Imported covers can use different measurements even when the size name sounds familiar.

Enter your own dimensions if yours differs. Every Lave insert is made to order. Enter your dimensions and choose a fill weight to see the price and buy directly.

5. Decide how you will care for it

Use a removable cover, read the insert’s care label and make sure you have a dry place to air it. If easy machine washing is essential, choose a product whose label explicitly allows it.