Fiber over count. Thread count per square inch matters less than many shoppers believe. Though the count has some effect on smoothness and durability, the type of cotton used is typically more significant.
Cotton types. Egyptian cotton is best because the cotton’s long fibers produce fabric that’s “sumptuous yet extremely long-lasting.” While pima cotton offers a worthy second choice, the label “100 percent cotton” usually indicates a product made with American upland cotton—“a rougher, less expensive variety.”
Percale vs. sateen. Both terms refer to the weave, and the choice is a matter of taste. Sateen is “very soft”; percale is thinner.
Blends. A 90/10 cotton-polyester blend can be a reasonable budget-minded choice. But avoid more than 30 percent synthetic: Such sheets “could make the sleeper sweat.”
Source: Real Simple