If you’ve ever shopped for sheets, you probably know that the phrase “thread count” refers to the number of threads per square inch — which is true. Of course, you may assume that the higher the thread count, the smoother and higher quality the sheets — absolutely NOT true. The entire concept of thread count is only useful for sheets made from single-ply cotton fabric. For any other material, it’s utterly meaningless. To understand why, you need to know a little bit about textiles. The “ply” of a fabric refers to the number of individual strands (or yarns) twisted together to make each thread. A single-ply thread has one yarn, a double-ply has two, and triple-ply thread has three. Therefore, single-ply cotton sheets are made of single-strand cotton threads. Here’s where thread count comes in: The finer the threads, the more of them you can fit into a woven fabric, and the smoother that fabric will feel. However, at some point, it becomes impossible to make a single strand of cotton any finer, which means there’s a limit to how many threads you can weave together. For single-ply cotton, that limit is 400-500 threads per square inch. So, if a set of 100% cotton sheets touts a threat count any higher than that, somebody’s lying to you. For a smooth sheet, anything with a 250-400 thread count is plenty soft.
