The thread count of a fabric is determined by the number of threads along one inch. The thread count of the fabric determines its density and generally gives you a good idea of its quality and softness to the touch. Usually, the higher the thread count, the better the fabric. However, there are other factors such as the fabric’s content that also impact the softness of the fabric. Some bed sheets are made of a blend of cotton and polyester that may make the fabric courser and less soft than a 100% cotton sheet. Also, even in 100% cotton sheets, it is important to look at the type of cotton the sheets are made of. Some 100% cotton sheets are made from less desirable species of cotton than others. More on this in another post. . .
Caution High Thread Count Alert:
Shopping for bed sheets can be tricky, because sometimes cut-rate linen manufacturers exaggerate the thread counts of their products. One way to do this is to twist gossamer thin threads around a central thread to overstate it. Be wary if you find an inexpensive set of sheets that claim to be 1000 thread count. If sheets truly are made of good quality 1000 thread count fabric, the price will not be cheap.
Take a look at my post about a sample set of 600 thread count sheets I tried out.