CARTONNAGE B20.02.00.54.000 Hinged-lid box, expansion-piece corners, three-winged lid

Length (A) Width (B) Height (H) Thickness

Lid height (Hₜ) Nicks

12×24 mat — 11.59″ × 10.60″

B11.02's corner on a two-double-wall tray, under B20.04.00.54.000's lid. Every corner closes on a diagonal fold, a web, and the two end walls fold back down inside themselves, each fold-back flaring a third of the height wider as it goes. Those wings wrap the corner and lap the side walls in front, which is the whole lock: the tray cuts nothing at all, where a nib-locked one needs eight. The lid drops over the outside, its own three walls folding back onto tabs that trap its webs. Ours, not a catalogue code.