Ralph Cleminson, PhD, was educated at Oxford and is Professor of Slavonic Studies at University of Portsmouth and Visiting Professor at CEU. Among his specialist interests are the palæography and codicology of medieval Cyrillic manuscripts. He is engaged in the application of new technology to the description and edition of medieval Slavonic sources. Elissaveta Moussakova, PhD is art historian. She works in the field of the illumination and codicology of medieval Bulgarian and Byzantine manuscripts. She is a Getty Foundation grantee, author of articles and studies published in Bulgarian and foreign magazines and journals, and visiting lecturer at CEU, Academy of Fine Arts and the New Bulgarian University. Nina Voutova, PhD is philologist, graduated from the University of Šumen (Bulgaria), the only Bulgarian specialist with a doctoral degree in filigranology. She works in the field of the usage and spread of paper in Bulgaria and in the Balkans, and is the author of articles, studies and catalogues published in Bulgaria and abroad. She has received grants from the Getty, Mellon and Fulbright Foundations and is a visiting lecturer at the New Bulgarian University and SUN (CEU).