First you need to decide what you want your sheets made of. Cotton is the most common and basic, but there's also linen, silk, bamboo, microfiber, etc... (I won't even get into all the blends out there.) Every material has its pros and cons: Linen is softer, more breathable ,and textured than cotton, but tends to wrinkle more. Silk is soft but more slippery. Microfiber is manmade versus natural. The list goes on, so you have to decide what feel you'd like.
This number is determined by the number of threads running both horizontally and vertically in a square inch. The higher the thread count, as the theory goes, the softer the sheets. A few considerations to keep in mind:
- You can only have so many threads per square inch, and with cotton, 400 seems to be a good number to look for. Once you hit a certain threshold, it really doesn’t matter and you won't notice the difference. (It’s almost like SPF ratings on sunblock or camera pixels.)
- There are ways for manufacturers to "increase thread count" without actually increasing the quality.
- It stands to reason that the number of threads you can squeeze into a specified area is dependent on the fiber that’s used. The thinner the fibers, the higher the thread count. Bamboo and silk have thinner fibers, so thread count can't be compared to that of cotton.
The best sheets are made from longer fibers that are stronger when made into thread. Egyptian, Sea Island, and Pima cottons are recognized as the best with the longest fibers, and sheets made with them are usually labeled as such. If the packaging simply says 100% cotton, chances are good they were made from shorter fibers.
- If the sheets are made from shorter fibers, thread count won't really matter that much. Over time those short fibers will break, produce lint and pilling, and become less soft to the hand.
How the threads are woven together has a big influence on how sheets feel on the bed. The most common are percale, sateen, satin, microfiber and jersey, for starters. Percale sheets, for example, are a simple weave and usually on the crisper side. Sateen sheets are softer, and have a shiny quality. Jersey sheets are stretchier, etc... and so forth. Price will go up depending on the complexity of the weave pattern used, with jacquard sheets being on the pricier end of the scale. Get to know what you like, and buy what you can afford.
Chemicals & Dyes
Many, many sheets are chemically treated after they are woven, to increase their strength and decrease wrinkling. If you want to avoid this (and the use of chemicals in general), look into treatment-free organic sheets.
To sum up, there are other factors than go into making quality sheets, and you can achieve softness a variety of ways. Don't let promises of high thread count sway you into ignoring those other elements.