Abstract: A removable stiffener for slip-in spectacle cases is formed by bending a sheet of resilient metal into a U-shaped structure approximating the cross-section of the spectacle case and lined on its internal concave surface with a soft, non-abrasive material. The stiffener is manually compressed prior to insertion into the spectacle case and is retained therein by the friction developed between its external surface and the inner walls of the case, due to its restrained expansion. The insert stiffens the case and prevents damage to the eyeglasses carried therein.