The boarding which fills in each opening of any piece of framing is called a panel.
Boards, except of American pine, can seldom be obtained of sufficient width to form panels in one piece, on account of shakes and other defects.
A joint down the panel is therefore generally necessary; this should, if the stuff is thick enough, be ploughed, and a slip feather be glued into it, which keeps the surface of the panel in a true plane and holds the joint together, so that when the panel shrinks it comes slightly away from the grooves in the styles, as it is intended to do.
The pieces thus used to form panels should be reversed alternately, so that the grain may run in opposite directions.
1 Sc. for Framed is Bound. 2 Known also as Mitntins.
A piece of strong canvas glued over the back of a panel will assist in keeping it together.
There are several forms of panels, known by technical names, depending upon the manner in which they are respectively constructed and ornamented.
The different kinds of panels now to be described are illustrated in Figs. 504 to 512, and in Plate XI. These figures are elevations and sections of doors, but the same constructions are used for panelling of all descriptions.
Square and Flat Panels 2 are those in which the boards are of the same thickness throughout, thinner than the frame, sunk square below its surface, and not ornamented by beads or mouldings.1 The panels marked A and B in Figs. 504 and 508 are "square and flat" 2 or " square " on both sides.