top and but

Top and but is a joinery method for building up width from two layers of tapered planks, used primarily in furniture and cabinet work. The technique involves offsetting the planks so that the thicker end (but) of one plank aligns with the thinner end (top) of the other, creating a composite panel of uniform thickness across its face.

The method solves a practical problem: long tapering boards are cheaper and easier to obtain than full-width stock, but a single tapered plank is too thin for structural work or aesthetic purposes. By layering two tapered pieces with opposite orientation, the maker achieves constant breadth without the waste of trimming to parallel edges. The planks are typically glued and sometimes cross-pinned or doweled to prevent racking.

Top and but appears most often in frame construction, where consistent panel thickness matters for joinery, and in solid wood tabletops where warping risk is reduced by the laminated structure. The technique requires careful matching of taper rates between planks. If the two pieces have different degrees of taper, the laminated panel will not present a flat face and glue joints will be under stress.

The terms come from plain English: the but (or butt) is the thicker end of a tapering board, and the top is the thin end. This is consistent with historical timber vocabulary where but referred to the heavy end of a felled tree. The pairing of opposites in the name captures the essence of the method: you are making thickness constant by placing thin and thick ends against each other.

This approach was common before modern planing mills made parallel-edged stock routine. It survives in hand-craft work and in contexts where salvaging tapered or irregular stock is economical. The method demands more careful fitting and gluing discipline than simple edge-joining of parallel boards, but it remains faster and less wasteful than hand-planing tapered stock to parallel edges.