I use a nylon Totes "duffle" bag with a side zipper, handles, and shoulder strap, for packing my kilt(s). The bag is the same length as my kilts and generally what I've found is that the kilt(s) travel best if placed on top of everything else in the bag. Because soft luggage is porous I place my kilt in one of those plastic bags from the dry cleaners prior to packing in order to prevent it from accidentally getting wet.