Fingermarks were collected from 13 donors with the Biomolecular Sciences Research Centre at Sheffield Hallam University without any exclusion criteria. Three fingermarks were collected per donor for a total of 39 samples under full SHU ethical approval ER52762288.
Fingermarks were sprayed-coated with a solution of alpha cyano 4 hydroxycinnamic acid using and HTX Technologies M3+ Sprayer (North Carolina, US)and then subjected to MALDI MS Imaging on the SELECT SERIES MALDI MRT (Waters Corporation, Wilmslow, UK). A total of 953 images have been used to train the model. Further details about the collection of the marks, the preparation and the analysis have been reported in the Study level documentation deposited within this collection. Detailed information on the model training process, including the scripts, algorithms, and training procedures, can be found in the Model Training & Inference section of the data-level documentation.