About Thread Count
Thread count is the number of threads woven together in a square inch. It consists of the vertical threads (the warp) and the horizontal threads (the weft) woven together. For years, it has been an incredibly popular way to determine the quality of fabrics used in sheets and bedding products. However, it may not necessarily be the most important factor. Fiber quality, yarn size, and finishing, all play important roles in the quality of a fabric.
A common misconception has been that the higher the thread count, the finer and softer the fabric. But that is not always the case. While sheet sets with 600 and 800 thread counts were once considered highly desirable and more luxurious, an optimal thread count for bed linens is really right around 400.
How is this so? It all depends on how the thread count is constructed. Traditionally, thread count equaled the total number of warp and weft yarns, based on using a single ply-yarn. However, in an effort achieve higher thread counts, manufacturers started using double-ply yarns as well as inserting multiple yarns (picks) into the weft.
In weave quality terms, the finest fabrics made with single ply yarns and have just one pick. The highest thread counts that can be achieved using this type of construction are in the 400-450 range. For higher thread counts such as 600 or 800, 2 ply yarns and/or multi-picks must be used. While the FTC has ruled that plied yarns should each only be counted as one thread when determining the thread count, this is not always enforced.