Even the collector himself at first didn’t know the paintings he hid in his studio called the Rainy Night would become so valuable decades later. Mr. Yi Ma, a man devoted to art collection, saved more than 200 pieces of oil paintings, sketches, and watercolors over the last 40 years. Oil painting made its debut in China early in the last century. Not many artists tried their hands at the western genre when it was first introduced into China, but Yi Ma’s collection includes oilpaintings by 50 Chinese artists in Even the collector himself at first did not know the paintings he hid in his studio called the Rainy Night would so so valuable decades later. Mr. Yi Ma, a man devoted to art collection, saved more than 200 pieces of oil paintings, sketches , and watercolors over the last 40 years. Oil painting made its debut in China early in the last century. Not many artists tried their hands at the western genre when it was first introduced into China, but Yi Ma’s collection includes oil preparations by 50 Chinese artists in