contrasting with the traditional Flemish style of painting in which the smooth surface—achieved by the application of multiple transparent glazes—conceals the brushwork. Bosch's paintings with their rough surfaces, so called impasto painting, differed from the tradition of the great Netherlandish painters of the end of the 15th, and beginning of the 16th centuries, who wished to hide the work done and so suggest their paintings as more nearly divine creations. Bosch did not date his paintings, but—unusual for the time—he seems to have signed several of them, although some signatures purporting to be his are certainly not. About twenty-five paintings remain today that can be attributed to him. In the late 16th century, Philip II of Spain acquired many of Bosch's paintings. As a result, the Prado Museum in Madrid now owns The Adoration of the Magi, The Garden of Earthly Delights, the tabletop painting of The Seven Deadly Sins and the Four Last Things and The Haywain Triptych. Painting materials Bosch painted his works mostly on oak panels using oil as a medium. Bosch's palette was rather limited and contained the usual pigments of his time. He mostly used azurite for blue skies and distant landscapes, green copper-based glazes and paints consisting of malachite or verdigris for foliage and foreground landscapes, and lead-tin-yellow, ochres and red lake (carmine or madder lake) for his figures. The Garden of Earthly Delights Bosch's most famous triptych is The Garden of Earthly Delights (c. 1495–1505) whose outer panels are intended to bracket the main central panel between the Garden of Eden depicted on the left panel and the Last Judgment depicted on the right panel. It is attributed by Fischer as a transition painting rendered by Bosch from between his middle period and his late period. In the left hand panel God presents Eve to Adam; innovatively God is given a youthful appearance. The figures are set in a landscape populated by exotic animals and unusual semi-organic hut-shaped forms. The central panel is a broad panorama teeming with nude figures engaged in innocent, self-absorbed joy, as well as fantastical compound animals, oversized fruit, and hybrid stone formations. The right panel presents a hellscape; a world in which humankind has succumbed to the temptations of evil and is reaping eternal damnation. Set at night, the panel features cold colours, tortured figures and frozen waterways. The nakedness of the human figures has lost any eroticism