Viscose is a type of rayon. It is a manufactured cellulose fibre, often referred to as ‘regenerated cellulose’. Therefore, it is neither natural (like cotton) nor synthetic (like nylon or polyester). It is semi-synthetic. A plant cellulose or protein is aquired. This is then processed to create a textile.
Viscose underwear has many benefits:
Breathability, therefore the underwear will help to ventilate you
Excellent colour retention, therefore the underwear colours will last wash after wash
Absorbency, so it will help to wick away moisture, keeping you dry for longer
Soft and therefore comfortable in underwear
However, viscose is more susceptible to shrinking if it is washed incorrectly. It can also crease more easily.