inexpensive sheets

Duvet fill weight is typically measured in grams per square meter (gsm) or ounces per square yard (oz/sq yd). It refers to the total weight of the filling material within the duvet, which directly correlates with the warmth and thickness of the bedding. A higher fill weight indicates a denser and heavier duvet, providing more insulation and warmth. Conversely, a lower fill weight suggests a lighter and less insulating duvet, suitable for warmer climates or personal preferences.

...

In 1689, English diplomat, Paul Rycaut visited Hamburg in Germany where he first experienced sleeping under a duvet. He sent his friends back in England some bags of eiderdown with instructions on how to make their own duvets and he also tried to sell the duvets himself. Unfortunately for him, the British people were not keen to embrace this new concept. It was prohibitively expensive, so instead, they opted to carry on using the more affordable sheets and blankets.

...