M. Graham watercolor paints were highly recommended to me. After reading reviews, I got overexcited and bought 10 15ml tubes. I bought an special pallet just for them. Initially I was completely satisfied. Fast forward 30 days of not being able to paint, and everything turned to some interesting fuzzy, green mold. Now I guess I will drill some ventilation holes. I never had this problem with Windsor-Newton. It makes me wonder about long term for paintings. Should there be any special care?