1. A method of analyzing a web of material containing at least two anomalies, comprising: receiving a web of material having upon it regularly spaced fiducial marks that uniquely identify a plurality of distinct positions on the web; receiving digital information that identifies regions on the web containing the at least two anomalies, and information defining the positions of the identified regions relative to at least one of the fiducial marks; as part of a web operation that is temporally distinguished from the web operations that yielded the web of material itself or the digital information and separated by at least a winding step whereby the web of material is wound onto a roll, unwinding the web and applying locating marks to the web identifying the position of at least one of the identified regions, using the positional information and the fiducial marks as a guide.