Classifying the typefaces of the Gutenberg 42-line bible

TL;DR

This study uses statistical cluster analysis to demonstrate that multiple matrices were used to cast metal types for the Gutenberg 42-line bible, challenging the traditional view of a single matrix per character.

Contribution

The paper introduces a statistical and clustering methodology to identify multiple matrices used in Gutenberg's printing, providing new evidence against the single-matrix theory.

Findings

Letters cluster according to shape differences

Multiple matrices were used for casting metal types

Low probability of classification error

Abstract

We have measured the dissimilarities among several printed characters of a single page in the Gutenberg 42-line bible and we prove statistically the existence of several different matrices from which the metal types where constructed. This is in contrast with the prevailing theory, which states that only one matrix per character was used in the printing process of Gutenberg's greatest work. The main mathematical tool for this purpose is cluster analysis, combined with a statistical test for outliers. We carry out the research with two letters, i and a. In the first case, an exact clustering method is employed; in the second, with more specimens to be classified, we resort to an approximate agglomerative clustering method. The results show that the letters form clusters according to their shape, with significant shape differences among clusters, and allow to conclude, with a very small probability of error, that indeed the metal types used to print them were cast from several different matrices. Mathematics Subject Classification: 62H30