Sunflowers have two main commercial uses, oil and confectionery (for direct seed consumption). Oil varieties of the flower have small, black, oil-rich seeds with thin hulls, which are pressed to produce an edible, almost tasteless, pale oil, rich in unsaturated fatty acids (especially oleic acid and linoleic acid). The oil is popular for cooking, margarine manufacture and even bio-diesel production. Leftovers from oil extraction are used to make high-protein animal feed. Confectionery types, on the other hand, have large, striped, oil-poor seeds with thick hulls. Both oil and confectionery types are the results of centuries of careful selection and breeding from wild plants.