The analysis of different inks on paper can be of great value. Especially if it is necessary to determine e. g. which signature on an important document was applied first or whether parts of a document have been changed after the document was signed.
Different inks normally show different characteristic SIMS signals. If the signatures overlap TOF-SIMS imaging can determine the sequence of application.
The example shows a large area scan from a document with print and two crossing signatures. The TOF-SIMS images of the two signatures clearly show that signature 2 was applied before signature 1.
Most paper surfaces are treated to obtain special surface properties. The treatment results in different lateral distributions of certain organic and inorganic surface species. These surface modifications can be investigated using TOF-SIMS.
The example shows the lateral distribution of certain organic and inorganic species on a paper surface.