LAUSR

Abstract This study aims at exploring the way paper samples may impact the performance of Single-Metal Deposition (SMD II), a fingermark detection technique known for its versatility of application as well as its sensitivity regarding porous substrates. To get a broader view on how porous substrates may impact the SMD II performances, 74 North American and European papers types were collected, characterized (UV–visible and infrared spectroscopy, roughness, porosity, and surface pH), and processed as substrates bearing fingermarks. This part of the study represented a first valuable outcome by the number of samples considered. After processing with SMD II, the samples were characterized again with the techniques mentioned above, background staining and fingermark quality were assessed and associated with a quality score. Overall, no positive nor negative trend was observed between the paper characteristics and the SMD II performance. As a consequence, it is currently still not possible to predict if a paper sample will behave well or bad with SMD II. Of all the monitored parameters, the chemical composition of the surface coating (i.e., silica or calcium carbonate) may be worth exploring further, as it has been observed that some coatings undergo partial degradation during the SMD II process. As a result, secretion residue may be damaged by the chemical solubilization of the support layer if they failed to penetrate deeper into the substrate.