The CretacoloR Aqua Monolith is a solid stick of water soluble pigment, 7mm in diameter and encased in a matching color layer of lacquer.  They can be used on the point for details, or the lacquer can be peeled off to espose the edge for making broad, sweeping marks.  Each pencil can easily be sharpened in a standard size pencil sharpener, and the shavings can then be dissolved in water and used as paint. 
MSRP $81.95