Are You Accidentally Damaging Your Valuable Kolinsky Brushes?

I got such a great tip from Gillian Condy, resident artist at the Pretoria Botanical Gardens, at our last mass demo painting: "Never ever wipe your expensive Kolinsky sable brushes on paper towels!" Paper towels are much too coarse and have the same effect as rubbing the delicate sable hairs against sandpaper - rather tear or cut a piece of material from an old cotton sheet, which is much kinder to sable.