Cotton or wool breechclout depending on weather or knee breeches. If you go with a wool breech clout , line the "working side" with light cotton cloth. You'll thank me.Oh, and most make their breechclouts way too long. I've seen them down past the knees. A proper length would be one barely peeking out below the shirt (depending on length of shirt). Best way to know is visit some sites like historical trekking. com and look at lots of pics. There's nothing cooler than a good pair of leggings and a proper breech cloth.