Patent ID: 8443725

Claim:
A method of non-destructively forming lines of weakness in a web formed from a fibrous structure, the method comprising the steps of: providing a device for printing a liquid weakener onto the web at a plurality of discrete locations extending generally in a cross direction of the web, the liquid weakener causing a bond between selected fibers within the fibrous structure to weaken; positioning the liquid printing device so as to be at least in close proximity to the web when the web is transported past the liquid printing device; supplying the liquid printing device with the liquid weakener to be printed onto the web to form the lines of weakness in the web at each of the discrete locations; transporting the web past the liquid printing device for printing the liquid weakener onto the web to form a perforation at each of the discrete locations; and controlling the liquid printing device for printing the liquid weakener as the web is being transported to form repeating lines of the perforations therein.