A finch, intensely focused on a moth, readies to strike its prey. It is perched on a citrus branch whose grapefruit and decaying leaves, like the bird and insect, have been rendered with naturalistic colors and impeccable detail. This style of painting, based on direct observation, is credited to the bird and flower painters of the Northern Sung Academy, especially as it developed under the leadership of emperor Hui-tsung (r. 1100-1125). These artists' small fan and album paintings demonstrate a balance of form, description, and decorative charm. Their technique generally rejects the use of ink outline and relies on the use of color alone (mu-ku or "boneless method"). The exact portrayal of closely observed objects drawn from life persisted in bird and flower painting into the early Ming period. The Chinese elevated plants and animals to artistic themes centuries before the west. They were also the first to render this type of subject matter with near scientific accuracy.