wet on wet painting

For this activity we used strong paper which we dipped in water (or can be wiped over with a damp cloth), then while the paper was still wet Finn painted on a washes of edicol dye (or food colouring) mixed up in empty baby food jars. The paper is fragile to work with, and can easily tear so encourage children to apply the paint gently. 

There is a lovely tutorial here: http://themagiconions.blogspot.com/2010/02/discovering-waldorf-wet-on-wet.html if you are wanting more details about the technique which is widely used in Steiner education.