Fill with water to blend lines and colors, add a favorite ink or dye, or add directly to a crayon to use them like paint. Easy-to-squeeze barrel and unique valve system allow for control of the flow of water. Flattened barrel keeps brush from rolling off the work surface. Durable nylon brush tip holds its point and is easy to clean; just squeeze out some water and brush it on a paper towel. Set includes fine, medium and bold points.