What are fitted sheets?  Most people know that fitted sheets also called a bottom sheet are used to cover the mattress on our beds. The four corners on a fitted sheet often have elastic sewn on the corners which helps the sheet to stay on the mattress. Fitted sheets are usually sold as a sheet set which includes the fitted sheet; the flat sheet and two pillow cases. With twin sets you only get one pillow case. Some stores will sell sheets individually called open stock.
Most mattresses have a standard with and length but some don’t have a standard thickness. This sometimes causes a problem to getting a perfect fitting bottom sheet.
The pillow top mattresses which are thicker need a wide or deep pocket fitted sheet. Before going shopping for new sheets measure the mattress you are buying for to make sure you get the right size fitted sheet.
The material of flat or fitted sheets weather you choose Egyptian cotton sheets or polyester blend is less significance to the quality than the thread count.
The thread count is the number of threads per square inch in the fabric, making it the best indicator of the quality you are getting when buying your sheets.