Environment has a great deal of influence when it comes to selection of fabric. Cold & wet I stay clear of cotton. On a flight line with jet engines and JP-4/5/8 I stay clear of polyester and nylon prefering cotton, wool & nomex depending on season. For high wear situations it's hard to beat nylon canvas such as the heavier weight nylon pants from 5.11 & RailRiders, but cotton and nomex have their place too.