OB Flat

In woodworking, "OB Flat" (often expanded to "Outside Back Flat") refers to a specific type of flat panel construction, typically used in the construction of cabinet doors and sometimes larger panels. It describes a panel that is intended to be viewed from the outside, specifically the back side of its construction. This means the visible surface is the back of the flat construction itself.

An OB Flat panel construction is often created by joining boards together to form a larger, stable panel. This joining can be achieved through various methods like gluing edges, using tongue-and-groove joints, or employing dowels or splines for reinforcement. The "flat" aspect refers to the generally planar and consistent surface created by these joined boards.

The primary characteristic defining an OB Flat panel is that the "back" of this joined panel – the side that might show more visible glue lines, minor imperfections from the joining process, or the ends of any joining aids like dowels – is intentionally presented as the outer, visible face of the cabinet door or panel. This is in contrast to a "FB Flat" or "Front Back Flat", where the "front" or visually cleaner side is used as the outer face.

OB Flat construction is often chosen for aesthetic reasons, particularly to showcase a rustic or handcrafted appearance. The slight imperfections and visual clues of the panel's construction are celebrated rather than concealed. It also offers a cost-effective approach, as less emphasis is placed on meticulously concealing all signs of the joinery process. Careful wood selection and joinery techniques are still essential to ensure structural integrity and a pleasing overall aesthetic, even when showcasing the "back" side.