The Rabbet

A rabbet is a step-shaped recess cut along the edge of a board. One piece sits in the step of the other, creating a joint that is flush on one face and overlapping on the perpendicular. In cabinet construction, the back panel sits in rabbets cut around the inside of the carcase. In a picture frame, the glass, the mat, the print, and the backing all stack into a rabbet running around the frame's inside perimeter, held by glazier's points pressed into the wood. The rabbet provides more glue surface than a simple butt joint and resists racking — the step prevents the pieces from sliding past each other under load. The word comes from Old French rabat, a beating down. The material is beaten back to make room for something else.

In a window sash, the glass rabbet is the L-shaped recess that receives the pane. The glass sits against the back of the rabbet, held by small metal triangles called glazing points pushed into the wood. Linseed oil putty — or modern glazing compound — fills the angle between the glass face and the wood, sealing the joint against water and wind. The putty weathers and cracks over decades; the glass may break; the sash may rot at its bottom rail where water collects. But the rabbet itself, cut into the solid wood of the frame, often outlasts everything it was made to hold. Re-glazing a window means removing everything from the rabbet and starting again. The step remains.

In wooden shipbuilding, the garboard rabbet is a groove cut along the full length of the keel to receive the garboard strake — the first and lowest plank of the hull. The angle and depth of this groove must match the plank's lie exactly. Too shallow, and the plank stands proud, creating a ridge that disturbs water flow and collects marine growth. Too deep, and the plank sinks below the keel surface, weakening the joint where hydrostatic pressure is greatest. The garboard rabbet is where the hull begins. Every other plank is fastened to the one below it, but the first plank has nothing below except the keel and its groove. The entire structure starts from one carefully cut step.

Three rabbets: a cabinet step that holds a back panel, a window step that holds glass, a keel step that holds the first plank of a hull. Each is a recess made by removing material — a deliberate absence cut into a solid surface so that something else can sit inside it. The rabbet does not grip. It does not fasten. It receives. And what it receives, it holds in place not by force but by the shape of the space it made.