And when was the duvet invented?

First of all, because linen’s flax fibers are slightly longer than those of cotton and wrapped a little tighter, linen sheets are stronger which means they will last much longer. If softness is a factor for you, you may want to consider cotton, though. Flax fibers are much rougher than cotton resulting in slightly crisper fabric. But the great thing about linen is that it gets softer after each wash, so essentially it gets better with time.

The most important thing to know about sheets is what they are made of. Materials will tell you a lot about how sheets will feel, their cooling and breathability, and their durability, as well as help you gauge if the price is fair.