As they tend to write other than on the table, I looked washable felt and that are less harmful. Actually in consideration the ink dries on the table, as I expected, and it is not possible that the child correctly clears his works. The trick therefore is to use a microfiber cloth with a little elbow grease!
I am happy because the ink is actually washable (both skin, walls that clothes!), And the color range is more varied than the classic black, green, blue, red.