A surface to which paint is applied or the material used to create that surface. A painting's ground is usually specially prepared on its support. Traditionally, for oil paint on canvas use a ground of oil and white pigment and on wood surfaces either an oil ground or gesso. Within a picture, ground may refer to a surrounding or background area. Also, in etching, it's an acid-resistant compound through which a design is drawn.
Example: Sam Francis often painted on ungrounded canvas.
Yü in Chinese, is a general term for numerous semiprecious gemstones, including nephrite (also called greenstone) and jadeite (a member of the tremolite-actinolite family of minerals), obtained as a pebble or boulder in greens and white, along with agate, onyx, serpentine, amber, and lapis lazuli. Extremely hard, it is worked with abrasives to form sculpture and ornaments, usually small in size, especially in China. During the Neolithic period primitive people almost universally used stone tools and carved decorative objects of jade-like stone. Only the Chinese, however, developed a long tradition of jade work. Other peoples stopped using the material after the Stone Age. Since Jade cannot be cut by metal, the carving process has mainly been that of abrasion. The original tools were probably slabs of sandstone and wetted abrasive sands made from crushed quartz, garnet, and corundum. Refinements in cutting, carving, drilling, and polishing techniques were developed gradually over time. Since jade working has always been laborious, requiring tremendous skill, jade objects were used for ceremonial, burial, court status, and other decorative purposes. They were rarely used as utilitarian objects.
In the late 19th century, European artists had their first glimpse at Japanese woodblock prints, provoking paintings that demonstrate a heavy influence of Japanese art on painters in Europe.
Example: Henri de Toulouse-Lautrec's At the Moulin Rouge, 1892-1895
Shaping a thin layer of clay over a revolving plaster mould with a shaped template or profile.