The best breathable underwear at a glance:What kind of fabric should your underwear be made from? In case you don’t already know, cotton and natural fibre are the ideal fabrics for your pants. “You do have a natural biome down there, so wearing natural fabrics is really important. No dryer“Absolutely do not put them in the dryer because natural fabrics will degrade at high temperatures, so you should always, always line dry your your knickers.” Final verdictSwitching to breathable underwear has increased my comfort levels by tenfold over the past couple of weeks.