Kids love paint. It is fun to paint in various mediums. I was thinking about St. Patrick's Day, which led me to think about potatoes, which led me to decide to do a potato print picture with Kaitlyn for St Patrick's Day.
I would say 18 months and up. 18 month old children can have fun with this, but don't expect them to make an actual picture. Just let them have fun with the paint and potato. Prints are an easy art project.
Potato--washed and cut in half
Plate for paint
Have your child dip the potato in the paint
Have your child press the potato on the paper. Have them press lightly
Take note that I just had Kaitlyn (2.5) have fun doing art. I didn't have her make a Shamrock. She giggled. She laughed. She exclaimed, "This is fun!"