IMOPORTANT: If needed, handwash with cold water and a little babyshampoo! And I mean by hand. A little added vinegar will keep colors bright. Dry flat.
I once got a call from a young father who was devastated because he ruined the babies hat by washing it in the washing machine. He told me his wife was very furious because it was her favoured hat for the baby. I was pressing "Hand wash" he told me. Yes, there is a button that says: "Hand wash" on most machines. But don't ever but it in the machine. Hand wash it with your own two hands. In the end the young father got a new hat for his baby by Tom's Grossmami and everyone was happy again. :)