Poppy oil

Poppy oil yellows considerably less than linseed oil. It maintains its consistency better when ground into thick, buttery oil paint (makes a nice “short” paint). Poppy oil can mitigate the fast-drying effect of some pigments to reduce internal tensions in the drying times of a paint layer. Excellent to use for wet-in-wet painting.
Poppy oil does not, however, become as hard when dry as other oils. It shouldn’t be used on fat, nonabsorbent grounds. Paintings done in poppy oil, especially with a heavier application, should be left unvarnished.