A ball-jointed doll is any doll that is articulated with ball and socket joints. In contemporary usage when referring to modern dolls, and particularly when using the acronyms BJD or ABJD, it usually refers to modern Asian ball-jointed dolls. These are cast in polyurethane synthetic resin, a hard, dense plastic, and the parts strung together with a thick elastic. They are predominantly produced in Japan, South Korea and China. The BJD style has been described as both realistic and influenced by anime. They commonly range in size from about 60 centimetres (24 in) for the larger dolls, 40 cm (15.5 in) for the mini dolls, and all the way down to 10 cm (4 in) or so for the tiniest of the tiny BJDs. BJDs are primarily intended for adult collectors and customizers. They are made to be easy to customize, by painting, changing the eyes and wig, and so forth.
The modern BJD market began with Volks line of Super Dollfie in 1999. Super Dollfie and Dollfie are registered trademarks but are sometimes erroneously used as generic blanket terms to refer to all Asian BJDs regardless of manufacturer.
Articulated dolls go back to at least 200 BCE, with articulated clay and wooden dolls of ancient Greece and Rome. The modern era ball-jointed doll history began in Western Europe in the late 19th century. From the late 19th century through the early 20th century French and German manufacturers made bisque dolls with strung bodies articulated with ball-joints made of composition: a mix of pulp, sawdust, glue and similar materials. These dolls could measure between 15 and 100 cm (6 and 39.5 in) and are now collectible antiques.
During the 1930s the German artist Hans Bellmer created dolls with ball-joints and used them in photography and other surrealistic artwork. Bellmer introduced the idea of artful doll photography, which continues today with Japanese doll artists, as well as BJD hobbyists.