Clothing is at times optional on the Appalachain Trail, but it is wise to be well prepared with a diverse line of clothing and outerwear. Most hikers thru hiking the trail will experience three seasons. Most will experience below freezing temperatures in the winter and scorching days in the summer.
Getting clothing that is versatile is the key to protecting your self and your budget. A pair of zip off pants is a better option than packing shorts and pants. Synthetic clothing is going to be lighter than natural fibers but is going to need washing more often than natural fibers. Many modern wool products are going to be as comfortable as cotton but are better perfroming and antimicrobial. The reps for Ice Breaker actual suggest you wear their products for up to seven days before you wash it... we'll leave that one up to you.