Daler rowney purified poppy oil is a clear oil medium that is used to mix with and reduce white and lighter oil paints you can use it to dilute oil colours and to apply colours as transparent glazes or to enhance gloss and flow purified poppy oil is less inclined to yellow than linseed oil but is slower drying this medium will enhance the gloss and flow of oil colours but adding too much of the poppy oil medium will retard thorough drying of the oil paint use equal parts of daler rowney po