If you are thinking of selling knitwear this autumn (or want to sort out some to wear) I have just discovered a fab way to de pill (sorry if this is well known but it's new to me and I am chuffed with it!!)
Use a Nitty Gritty long metal nit comb and carefully skim the surface of sweater placed on flat surface like the ironing board - (make sure you hover not let prongs catch) it works an absolute treat! The nitty gritty works way better than the small plastic ones which have shorter teeth - I just did comparison test.
I just made my fave Cos super soft jumper look perfect again :-)