Finally, because censorship and moral policing have often prevented artists from making work that is openly erotic, it is worth drawing attention to the existence of covertly erotic art, that is, art made with the covert intention to stimulate its target audience sexually and that succeeds to some extent in doing so. A good example are the so called “sukashi shunga” (hidden shunga) that were popular in Japan at the beginning of the 20th century. Shunga are woodblock prints, often created by Japan’s leading artists, depicting highly erotic scenes. While there were already regulations in the early 18th century against the distribution of shunga, it was only at the end of the 19th century, in the wake of Japan’s increasing openness towards the West, that censorship laws were really being enforced. As a result, hidden (see-through) shunga prints were designed to escape the strict eye of the censor. What at first sight appear to be beautifully drawn postcards depicting landscapes with some space in the middle and at the corners to write one’s message, when held up to the light, turn out to be sexually explicit lovemaking scenes (Aki 2013: 47). An example of an entirely different kind might be Vermeer’s Milk Maid (1657–58). Given that milk maids had a reputation for sexual availability in 17th century Holland, some scholars have argued that the painting has a covert erotic message, with the foot warmer on the floor suggesting feminine desire (because foot warmers would heat not only the feet but everything under a woman’s skirt) and one of the Delft tiles in the scene depicting Cupid, while another tile shows a traveling man possibly suggesting that the maid is thinking of an absent lover (Liedtke 2009).