New Contributions to the Systems of Obtaining Data on Watermarks and their Application as a Useful Tool to Monitor the Processes of Restoring Graphic Documents

This study is a review of the systems to measure watermarks and ‘fingerprints’ and investigate their validity as tools to monitor the processes of restoring graphic documents. The findings of the different tests carried out indicate, on the one hand, that the digital microscope is the best, most direct and fastest system for said purpose and, on the other hand, show that in the restoration methods applied there is almost no dimensional variability in the paper and that this is due, mainly, to the process and the degree of humidity introduced, as well as the relative humidity of the environment.