Groundpiece hinge-fold leather cracking
The Groundpiece (Antonio Citterio, 2001) low-recline mechanism is its defining design characteristic -- and its primary failure point. The arm hinge flexes full-grain aniline leather repeatedly at one concentrated point, developing fine surface cracks at year seven to eleven on unprotected hides. Owners who apply commercial conditioners seal the surface and accelerate the crack propagation. The same failure pattern appears on B&B Italia modular arm hinges and aniline leather in general at high-flex points. Cracking repair detail is here.