When looking to buy bed linen, it is true - high thread counts definitely make better bed linen, but it's the thread that matters the most. In fact, a sheet of a better-quality fibre but a lower thread count will feel softer and stand up to washing better than a sheet of a lower-quality fibre with a higher thread count.
So what should you look for?
Cotton-polyester blend sheets are wrinkle-resistant, reasonably inexpensive and durable – this is because polyester lasts longer than cotton. But if you are wanting a cool, soft feel, nothing beats 100% cotton. You'll hardly ever wake up feeling clammy on cotton sheets, this is because the fibre wicks moisture away from your skin. Cotton sheets are also less likely to stain than polyester blends, cotton releases dirt easily when wet.
The weave can affect the way a sheet feels, the way it looks, its longevity, and its price. Basic plain weaves, which are woven from an equal number of vertical and horizontal yarns, are least expensive and may not rate a mention on the label. Percale is an upscale plain weave with a thread count of 180 or higher and is known for its longevity and crisp feel.
Sateen weaves have more vertical than horizontal yarns. The higher proportion of vertical threads results in an extremely soft fabric, but it also means its more likely to pill and tear than a plain weave. Intricate weaves, such as jacquards and damasks feel textured, with a pattern alternating from satiny soft to coarser and nubby. They can be as durable as plain weaves, but they are made on special looms and are considerably more expensive.
Most sheets are treated with chemicals (including chlorine, formaldehyde, and silicon) to keep them from shrinking, losing their shape, and wrinkling. Some are treated with alkalis to produce a sheen.
A handful of manufacturers offer pure-finish sheets, meaning that no chemicals were used or that all traces of chemicals used during manufacturing have been removed. You'll have a harder time keeping these sheets wrinkle-free, but it may be worth it if you suffer from allergies or chemical sensitivities.
Patterns and colors are usually applied to sheets after they are woven, this means your sheets may feel stiff until they have been washed a few times. The softest (and most expensive) coloured or patterned sheets, including jacquard weaves, are made of yarn-dyed fabrics, woven from coloured yarns.