How do scholars compare handwriting to identify a medieval scribe or notary?

In the field of diplomatics, scholars identify medieval scribes and notaries by analyzing their handwriting, which serves as a critical tool for dating and authenticating documents.1

Paleographers study the specific mannerisms and stylistic habits of individual scribes, which can be highly distinctive. By tracking these characteristics over time, experts can trace a scribe's career through the development, maturity, and eventual deterioration of their handwriting. This process involves several key methods:1

• Script Identification: Certain centers, such as royal or papal chanceries and monastic scriptoria, developed unique, identifiable styles of handwriting that often serve as a signature of their origin.1
• Individual Mannerisms: Even anonymous clerks who produced routine property conveyances can be identified by consistent features in their script over many years.1
• Professional Markers: First-rate scribes, particularly notaries public, often provided explicit information about themselves, including their names and unique notarial signs, which aid in identification.1
• Comparative Analysis: Scholars compare unknown hands against known samples from specific offices or periods, though they must exercise caution, as different scribes might work in the same office, and some styles remained in use for generations.1