I have half a dozen or so. All of them are Washed after each use, warm wash with one of the race suit detergents, dear but a little goes a long way and i like the smell.
Tumble dried, my drier gets no where near as hot as my R300 did, and then folded and stuck back in the bag. Never had an issue with any of them. Have Sparco, Alp stars and OMP. The OMP's are by far the best quality.
Hope that helps.