ECMA B11.02.00.00 Four-double-wall tray, locking corners, expansion piece

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

Nicks

12×24 mat — 8.96″ × 11.83″

Unglued selflocking tray with 4 double walls with locking corners; locking flaps system with fold over ends with expansion piece. Every corner still closes on a web — one diagonal fold — but the end wall's fold-back flares a third of the height wider as it rises, and those wings are the lock: folded, each wraps the corner and laps the side wall in front, not behind it. The side walls' own fold-backs taper away at the catalogue's 15°, which is the expansion piece and what leaves the wings room to land. ECMA catalogue, p.36 ↗