well i do not wash mine due to two things. one is tradition and the other is that there's a new fad out there that if you wash your black belt it will fade and fray faster, which apparently is the new 'look' for martial artists. people opinions on not washing them due to tradition is different and that's all well and good, not washing it is just the way i do it. i work very hard during classes and have had my black belt for many years and have not had a problem with smell that some people talk about, so if you dont have to then i wouldnt risk it. yes, it will shrink slightly but hardly much at all prob like a quarter inch, if that. and yes, the color will start to fade, referring back to that whole 'fad' thing. you can absolutely wash a cotton belt, but satin, i wouldnt, i'd hand wash that and hang dry at the most. but good luck with whatever you chose to do. about washing a belt..... it's just a myth, in japan almost everybody (sensei, master etc) wash their belt after the training, in okinawa too.... it's a myth like the belt touching the floor etc!!!