An Examination of the Sequence of Intersecting Seal and Laser Printing Toner Line

Examining the sequence of intersecting seal and laser printing line is a significant method of determining the authenticity and validity of documents. In this study, five brands of stamp pad inks, three types of inkpads and seven kinds of laser printers were used to make heterogeneous line intersections. Observation method of physical characteristics, scraping technique and fluorescence method was used to determine the sequence of intersecting lines. Distinguishing features were noted between the materials produced in both sequences. As the results obtained from the study were positive, these features might provide a scientific basis for accurately determining the sequence between laser printing line and inkpad (stamp pad ink) seal.     

The Examination of Commercial Printing Defects to Assess Common Origin,Batch Variation,and Error Rate*

Abstract: The examination of printing defects, or imperfections, found on printed or copied documents has been recognized as a generally accepted approach for linking questioned documents to a common source. This research paper will highlight the results from two mutually exclusive studies. The first involved the examination and characterization of printing defects found in a controlled production run of 500,000 envelopes bearing text and images. It was concluded that printing defects are random occurrences and that morphological differences can be used to identify variations within the same production batch. The second part incorporated a blind study to assess the error rate of associating randomly selected envelopes from different retail locations to a known source. The examination was based on the comparison of printing defects in the security patterns found in some envelopes. The results demonstrated that it is possible to associate envelopes to a common origin with a 0% error rate.     

Examination of heterogeneous crossing sequences between toner and rollerball pen strokes by digital microscopy and 3-D laser profilometry

The determination of line crossing sequences between rollerball pens and laser printers presents difficulties that may not be overcome using traditional techniques. This research aimed to study the potential of digital microscopy and 3-D laser profilometry to determine line crossing sequences between a toner and an aqueous ink line. Different paper types, rollerball pens, and writing pressure were tested. Correct opinions of the sequence were given for all case scenarios, using both techniques. When the toner was printed before the ink, a light reflection was observed in all crossing specimens, while this was never observed in the other sequence types. The 3-D laser profilometry, more time-consuming, presented the main advantage of providing quantitative results. The findings confirm the potential of the 3-D laser profilometry and demonstrate the efficiency of digital microscopy as a new technique for determining the sequence of line crossings involving rollerball pen ink and toner.     

化学显色法分析喷墨打印机黑色墨水的种类

目的建立化学显色法检验喷墨打印机字迹色痕的方法。方法选用不同的试剂或混合试剂,对22种不同品牌的喷墨打印黑色墨水的溶解性及与不同试剂的颜色反应进行观察。结果不同品牌的喷墨打印机黑色墨水的溶解性不同,与不同试剂作用会显现不同的颜色。结论化学显色法快速、简便,可用于现场的快速检验。     

针式打印文件检验的探讨

针式打印机是一种常用的办公机具,从针式打印机的结构和打印原理出发,阐述了针式打印文件种类鉴别和个体识别所依据的打印特征,为针式打印文件的检验鉴定进行操作层面的探讨。     

Testing a Novel 3D Printed Radiographic Imaging Device for Use in Forensic Odontology

There are specific challenges related to forensic dental radiology and difficulties in aligning X‐ray equipment to teeth of interest. Researchers used 3D printing to create a new device, the combined holding and aiming device (CHAD), to address the positioning limitations of current dental X‐ray devices. Participants (N = 24) used the CHAD, soft dental wax, and a modified external aiming device (MEAD) to determine device preference, radiographer's efficiency, and technique errors. Each participant exposed six X‐rays per device for a total of 432 X‐rays scored. A significant difference was found at the 0.05 level between the three devices (p = 0.0015), with the MEAD having the least amount of total errors and soft dental wax taking the least amount of time. Total errors were highest when participants used soft dental wax—both the MEAD and the CHAD performed best overall. Further research in forensic dental radiology and use of holding devices is needed.     

掀起伪造印章的面纱来

近几年来,随着计算机技术、照排技术及打印与印刷技术的普及与提高,利用伪造印章进行违法犯罪的现象日益突出,而且手法不断翻新,伪造痕迹愈加隐蔽。通过分析伪造手法中存在的共同特征及常见印章伪造所形成的特征,为掀起伪造印章的面纱提供途径与方法,实现司法公正。     

胶印同版印刷品的检验与鉴别

印刷品同版鉴别作为印刷文件检验的技术手段,一直是文件检验鉴定领域的研究热点之一。由于胶印印刷方法的广泛应用,在各类案件中经常使用胶版印刷品的同版检验技术,本文首先介绍了平版胶印的基本原理,阐述了平版胶印文件的特征,从总观特征和细节特征两个方面论证了胶印同版检验鉴定问题,并结合案例重点讨论了同版印刷品的鉴别问题,最后说明了在进行胶印同版检验鉴定中,检验鉴定人员要有严谨细致的工作作风,只有充分发掘检材和样本上的细节特征后才可以科学、准确的给出鉴定结论。     

Establishing of chemical composition of printing ink

The subject of the examinations was primarily court tax marks of 50 and 200 PLN, which were suspected not to be genuine. Both inks on the questioned marks as well as comparative genuine marks and inks sent by the manufacturer were analyzed. No information about their chemical composition was available from manufacturer. In the examinations, infrared (IR), visible, X-ray fluorescence, and Raman spectrometry were used. The examinations showed that inks and glue on the marks of both values were the same as samples of those sent by the manufacturer. Discrepancies in some results were observed probably due to contamination, that is, an accidental presence of the foreign substance on the surface (e.g., sweat, saliva while sticking the marks to the surface or physical handling of the documents). It was concluded that there are original (genuine) court tax marks.