Firstly, thread-count (or TC), in its purest sense, means the number of threads that a sheet contains in a square inch of fabric. (So, if you have some sheets and don't know the thread count of them, cut out a square-inch patch and pull apart the threads and count them up.) Thread-count can range anywhere from 80 to 1000 or more. Generally, the higher the TC, the better and softer the sheets are supposed to be. However, judging sheets on TC alone is not the end-all-be-all of guides to sheet buying but is simply a quick and dirty "rule of thumb". If you don't have the time nor patience to do further research, then you're probably pretty safe looking only at the TC. There are a few instances when doing this might result in you not getting the best sheets, but more about that later. The first factor to consider is if the cotton has been "combed" or not. Combing (a process I will not bore you with the details of - let's just say it involves a comb ...) removes undesirable fibers from cotton before it's spun into yarn for weaving. By doing this, the spun cotton becomes more durable and softer to the touch. So, a sheet made of 200TC combed cotton will feel softer than sheets made of 200TC un-combed cotton. Another factor that affects sheet comfort is the weave. There are two, common types: Percale - This is the standard weave, most sheets - even if it's not specified - probably employ this method of manufacture. It's a closely-woven structure that relies on a simple "one over, one under" construction. (Think: Making a pot-holder in summer camp.) Percale will yield a duller finished product. Sateen - This weave gives sheets a soft, satin-like feel with a glossy look. The structure is a "four over, one under" design which places the most threads on the surface. However, this method makes the fabric less durable than other weaves. Probably the most important factor to consider when buying bedding is the type of cotton used in the fabric. Since cotton can vary greatly in quality, the type used is even more important than TC. The types of cotton out there are: Muslin - Very low-end cotton. Most manufacturers use this type to make cartoon-printed kid's sheets. (Mainly because kids don't know to ask mom and dad for better sheets and, anyway, mom and dad don't care how comfortable the kid's sheets are. And manufacturers know this.) Sheets made of muslin usually have a TC range of 128-140. Pima or Supima - This is the second-best quality of cotton on the market. It feels soft to the touch and usually has a TC range of 200-300. Egyptian - The higher-end cottons available. Historically, this cotton was all imported from Egypt (thus, "Egyptian"), but, alas, that's not the case anymore. No matter where it's grown, however, Egyptian cotton is known for its superior durability, luster, silky feel, and usually has a TC range of 200-400. To put all of this information into perspective, sheets that are made from uncombed 80TC Percale muslin will feel like sandpaper and sheets made from combed 1,000TC Sateen Egyptian cotton will feel like clouds. Puffy, puffy, marshmallow clouds. One last note: The idea of thread-count-as-guide goes out the window when talking about linen, flannel, bamboo (yes, like the plant), or jersey sheets, since the threads that are used to make these kinds of sheets are thicker than threads for regular cotton sheets. In fact, most jersey, flannel, and bamboo sheets don't even bother putting a TC on the label. For these sheets, the type of fiber is more important to how they feel. Myself, I'm partial to bamboo. Stay informed on all deals on sheet sets via dealnews' Bed & Bath section. (Email and RSS alerts are available.) Intrepid reporter, Jeff Somogyi, is looking out for YOU, America! He also likes to sleep a lot. In comfortable sheets, if possible.