Deep mattress sheets are perfect for thicker mattresses because they are made to suit a lot better. Deep sheets can be found in several materials including egyptian cotton and flannel. Particular fabrics tend to be more suitable for specific months and climate conditions therefore you may want to choose a warmer material for cold months plus a much cooler fabric for summer months. They are also available for purchase in an array of thread counts. The higher the threads count the better the level of quality. Any thread count of 300 to six hundred is great for standard use. There are plenty of online retailers that offer deep pocket sheets.