Thread Count is only one measure of the quality of luxury linens. It's helpful to distinguish how thick and dense a fabric will be, but it doesn't tell you how the cloth was woven, sewn or finished.
Fine Italian sheets, historically, have been from 270 thread count to around 380 thread count. Don't get fooled by numbers like 1500 and 1800 - it's just plain misdirection. Cotton, and blended cotton woven sheets do not have thread counts that high. Even if there were, the technique used to weave them would create a sheet with inherent flaws in dimensional strength and washability.
