As we're into supporting Portuguese brands, we like to mention BOVI , Bordalima and Sampedro as three major quality brands for bed linen we buy from at the fabulous store in Chiado : Paris Em Lisboa .
We go for 100% cotton with great softness : a minimum thread count of 300 and often in percale fabric ( a closely woven plain-weave fabric, imported from India in the 17th century with a history going back as far as the 14th century ).
For true fabric geeks, here's lots more info from Wikipedia :)
Thread count is a measure of the fineness of fabric. It is measured by counting the number of threads contained in one square centimeter of fabric, including both the length (warp) and width (weft) threads. It is used especially in regard to cotton linens such as bed sheets, and has been known to be used in the classification of towels. In general, the higher the thread count, the softer the sheet, but the weave and type of thread may affect the "hand" of the material so that a sheet with a lower thread count may actually be softer than one with a higher count. Yarn quality also plays a part in the look and feel of sheets, as finer yarns tend to create a finer sheet fabric. The ply also plays a role in how heavy the sheet feels. Ply represents how many fibers are twisted together as the sheet is being created. A 2 ply 300 thread count sheet will feel heavier than a single ply 600 thread count sheet.
Or a nice video
On that note, we wish you a fine night in bed :)