- J-box
- See "Junction Box".
- Jacobean
- A period in English design from 1603 to 1688. Characteristics include jeweled strapwork, interlaced guilloches and banding, and checker patterns. Also known as late Tudor.
- Japanning
- A technique borrowed from Japan where furniture and metalwork are detailed with colored shellac in raised patterns, then painted primarily with golds, blacks, and reds.
- Jasperware
- The name given by Josiah Wedgwood to the matte, white clay that can be colored and decorated. Often these objects were finished in blue grounds and resembled cameo plaques.
- Junction Box
- A metal or plastic enclosure providing the point of service connection between gas pipes or electrical wires and the equipment they power. One hangs a chandelier from a junction box and connects the trunk line of the chandelier to the supply wires in the box. See also "J-box".
