1. A method of determining a level of similarity between a feature in a subject document and expected characteristics of said feature, the method comprising: a) obtaining a digital image of at least a portion of said document; b) isolating said feature in said digital image c) gathering data from an analysis of said feature d) comparing data gathered in step c) with expected data from expected characteristics of said feature e) generating a score based on a comparison between said data and said expected data wherein said expected characteristics are based on methods used to manufacture said subject document.