Duo is a water-soluble oil paint. It can be softened or diluted with water. Since I can create without using volatile solvents, my atelier is always comfortable. Additionally, Duo mixed with water allows for expressions that cannot be achieved with traditional oil paints. For example, it is a paint that further expands the possibilities of oil painting expression, such as hatching with thin, dark lines, and painting texture that takes advantage of the unique flow and blurring of water.20ml (No. 6 tube) 11 colors + 1 bottle of 50ml (No. 10 tube)