My kiddos love to get their hands dirty and on a rainy day finger painting is a fun way to do that. Amazon  has a 4 pack of Crayola Washable Fingerpaints  for $4.88(originally $7.99). They do qualify for free shipping with an order of $25 or more.
These would make a great teacher gift for the end of the school year. They would also make a great birthday gift for kids 5 and under.
If interested check it out now because Amazon  prices can change quickly.