Frame and panel

Frame and panel construction, also called rail and stile, is a woodworking technique often used in the making of doors, wainscoting, and other decorative features for cabinets, furniture, and homes. The basic idea is to capture a 'floating' panel within a sturdy frame, as opposed to techniques used in making a slab solid wood cabinet door or drawer front, the door is constructed of several solid wood pieces running in a vertical or horizontal direction with exposed endgrains. Usually, the panel is not glued to the frame but is left to 'float' within it so that seasonal movement of the wood comprising the panel does not distort the frame.

Frame and panel construction at its most basic consists of five members: the panel and the four members which make up the frame. The vertical members of the frame are called stiles while the horizontal members are known as rails. A basic frame and panel item consists of a top rail, a bottom rail, two stiles, and a panel. This is a common method of constructing cabinet doors and these are often referred to as a five piece door.

In larger panels it is common to divide the panel into one or more sections. To house the extra panels, dividing pieces known as mid rails and mid stiles or muntins are added to the frame.

The panel is either captured in a groove made in the inside edge of the frame members or housed in an edge rabbet made in the rear inside edge. Panels are made slightly smaller than the available space within the frame to provide room for movement. Wood will expand and contract across the grain, and a wide panel made of solid wood could change width by a half of an inch, warping the door frame. By allowing the wood panel to float, it can expand and contract without damaging the door. A typical panel would be cut to allow 1/4" (5 mm) between itself and the bottom of the groove in the frame. It is common to place some sort of elastic material in the groove between the edge of the panel and the frame before assembly. These items center the panel in the frame and absorb seasonal movement. A popular item for this purpose is a small rubber ball, known as a spaceball (a trademarked product). Some cabinet makers will also use small pieces of cork to allow for movement. The panels are usually either flat or raised.

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Wikipedia