500-thread count covers

the weave has 500 threads per inch. It's usually used to refer to cotton cloth sheets and indicates a very thin, strong cotton thread, like Egyptian long-staple cotton, very tightly-woven, high quality, fabric, often very expensive. Cheap sheets start at about 200 count, 200 threads per inch, and they feel really coarse if you sleep on them. a 500 thread count pillow cover would probably not allow any of the down to escape, as a coarser cover might.