The sequence of intersecting lines may play an important role in the forensic examination of a document. The determination that elements of a document were prepared out of the proper sequence provides evidence that the document has been altered. While most line intersection problems involve writing inks, they may also involve typewriting, computer‐printed text, paper folds, and indentations. Many methods have been suggested to determine the order of intersecting lines. Some are more effective than the others. This article reviews a number of techniques.

There has been a recent increase in the use and availability of full-color copiers. With this increase comes a greater potential for criminal use. Research by the authors has shown that many products of full-color copiers can be differentiated by the use of microscopy, infrared luminescence, infrared reflectance, and laser luminescence.