continuously moving glass ribbon typically involves first scoring the glass ribbon and applying a tensile stress across the score to create a crack and then driving that crack through the thickness of the ribbon the score may be formed by any conventional method for example the score may be produced by contacting the ribbon with a scoring wheel a scribe or an abrasive member that creates surface damage to the ribbon the subsequent tensile stress is applied by bending the glass ribbon in a direction that places the scored side of the glass ribbon across the score line in tension the tension in turns drives the crack formed at the score line through the thickness of the ribbon because the glass ribbon is a continuously moving glass ribbon having a viscous portion a visco elastic portion and an elastic portion care must be taken during the drawing process to prevent perturbations induced into the ribbon such as during a cutting process from propagating upward to the visco elastic region where they may become frozen into the ribbon as the ribbon moves continuously downward and the viscous portion transforms from a viscous liquid to an elastic solid the viscous portion is continuously renewed and the elastic portion continuously removed so that the viscous portion the visco elastic portion and the elastic.