Abstract: A method and apparatus for use with a web of material having a web length dimension and a web surface, the method for placing mark sequences on the web surface every X distance along the web length dimension identifying location along the web length dimension, the method comprising the steps of monitoring web location, every X distance, placing a sequence of N marks on the web surface along the web length wherein each two adjacent marks define a space length dimension and wherein the pattern of space length dimensions formed by the N marks in the sequence together specify a specific web length location. The invention also includes a marking and defect locating system including a high speed printer and a high resolution, high speed camera to facilitate the methods.