If you invest in a trad kilt from good kilting tartan, it will be pretty indestructable provided that:

-you wear a sporran with a _leather_ strap. A chain will wear a good kilt out over time where it rubs on the wool

-you keep the moths away to avoid holes.

Kilting worsted will not pill, but it _will_ fade. Red is particularly notorious for fading. Our oldest 16 oz band kilts were new in the early 90s. They show essentially no wear, but they are noticeably faded when you compare the top apron and the underapron.

Moral of the story - if you wear your kilt in the sun, it will fade. Unavoidable. But you can make the problem worse by leaving your kilt lying in the sun or hanging it on the line airing in the sun.

Barb