the thickness of microfiber sheets is actually measured in GSM. Depending on the Brand you are purchasing the thread count Rating May vary to the actual GSM of the Sheets. For Example: One Brand may be 75GSM and Rate it as 800 TC and the next brand may be 80 GSM and rate it as 800 TC. Microfiber Sheets have a higher thread count than cotton, but are often thinner and lighter than cotton because the fibers are so small. When purchasing any microfiber sheets it is a good idea to ask what the gsm measurement is. The higher the GSM Rating, the more fibers in the sheet set and the thicker the sheets will be. Because microfiber is lightweight these sheets do no wrinkle and are very breathable, which is great for warm summer nights.