Being a men’s underwear shopper you are most likely aware of the multitude of different fabrics and fabric blends offered by the various underwear brands. What’s also very likely is that beyond cotton, and possibly spandex, you don’t really know what the different fabrics are like, how they will feel against your skin and what the best time of year to wear them is.

To save you the trouble of finding out by trial and error, here’s a guide to the most common fabrics and what you can expect from them.

Cotton: This is the classic go-to material for undies and all sorts of other apparel. The best qualities of cotton are its softness, breathability and being very comfortable to wear. However, cotton undies have almost no shape retention and will begin to sag long before the day is done. Also, during sweat-intensive activities, there is a high risk of chaffing from cotton undies, as cotton absorbs moisture rather than wicking it away.

Viscose or Rayon: This fabric is made from plant materials and is one of the first man-made fibers. It is used in a wide variety of apparel, but is absolutely perfect for underwear. It is as soft as silk, light and breathable, and has excellent moisture wicking capabilities. However, it is a dense fabric, so it can feel a little heavy, and it will loose its shape quite quickly.

Modal: This fabric used to be known as “artificial silk” and is a form of Rayon. Undies made from this material are soft, cool and feel a lot like silk to the touch. This material is also very absorbent, and will not fade in the wash as easily as cotton. It is a perfect choice for those hot summer days and nights, but might prove a bit too cool for winter. Just like cotton, it is not the best choice of underwear for vigorous workouts. One of its derivatives is the so-called MicroModal®, which is one of the best choices for underwear, since it is lightweight, moisture wicking and very durable.

Nylon: This is a synthetically engineered material that was originally made to replace silk, though you’ll probably agree that it wasn’t the best attempt. However, nylon is awesome for wearing during workouts and other sweat-intensive activities. It’s durable, lightweight, will not get damaged easily and has superb moisture wicking capabilities.

Bamboo: this fabric is still quite a novelty, though some brands are already offering undies from this material. Basically, this fabric is constructed from the pulp of bamboo grass and is very breathable, lightweight and tough. What’s more, it also possesses moisture-wicking properties and also some natural antibacterial protection.

Spandex or Elastane: This is a man-made fabric that offers elasticity to garments. It is a more common alternative to latex and is very moisture resistant and light. On the whole, most underwear styles today (with perhaps the exception of boxers) contain at least 5-10% spandex. Even cotton with a touch of spandex will stay put tight against your skin all day long.

So that’s it for the most common fabrics found in the world of men’s underwear. As a rule of thumb, you can’t go wrong with cotton mixed with a bit of elastane. However, in the hot summer months, undies made from rayon or modal are also an excellent choice. For sports, your best bet is to opt for something more on the synthetic side.