How to choose bed linen for a sweeter sleep

Weave density
Another aspect to consider. Weave density is the number of threads per square inch of fabric. Denser fabrics are less breathable, but keep you warmer, while fabrics with a lower density may fray more quickly but dissipate heat well.

Weave density is usually indicated by a three-digit number: 200, 300, and so on. There are also measurements in grams per square metre. The scheme is the same: the higher the number, the denser the fabric.