It is best to store your clay in a cool dry place, away from sunlight and heat to prolong its shelf life and keep it from crumbling into flaky pieces.
I store mine inside tight lid tin cans and as much as possible, use the same plastic packaging in keeping it separated from each other. Otherwise, you can use wax paper to keep the clay of different colors segregated. You can also use food grade plastic or Ziploc’s. Clay tends to react badly in plastic containers, according to some books I’ve read so better watch out for that one.
