NEW YORK: Heidi Klum keeps her children’s hair to make art with.  The supermodel didn’t want to part with her sons Henry and Johan’s big afros when she cut their hair for the first time and so decided to put their shorn locks in plastic bags.  Heidi - who confesses she is a hoarder who ‘’keeps everything’’ - was initially unsure of what she was going to do with her unusual stash, but then decided the hair would be perfect to use when painting with her boys.  Speaking to website YourTango at the Shutterfly by Design home décor event in New York City, she said: ‘’So two of my boys, they have big afros,–SS