Let's start at the beginning. One of the fundamental features of the book before print is handwritten letters: those carefully crafted symbols that fill up page after page to convey meaning. Each one of us writes differently today, and considering that medieval books were handwritten before the invention of print, it follows that the letters they carry likewise show a great variety in execution styles. This is perhaps the most amazing aspect of spending a day paging through medieval books in the library: the immense variation in how the text was written down, by the hands of medieval people, onto the page.

No surviving artifact underscores this point better than the advertisement sheets of commercial scribes (Figure 102 at p. 196). Many of them even wrote the names of the scripts next to the samples, some in appealing golden letters, like good marketing men. Providing the names of scripts also allowed customers to converse with the artisan in precise—specialist—terms. Figure 19 at p. 29 probably shows such a transaction between a commercial scribe and his client, whose greetings are extended to each other in text strips called “banderols” (about which, see Chapter 12).

In the wild party of letters seen in advertisement sheets, two categories of variation can be observed: first, the shape of medieval letters differs because they belong to different script families; and second, their precise execution varies because the scribes opted for a particular size, thickness, quality, and pen angle. Remarkably, this variation is still preserved in our modern typefaces, which represent families of fonts, and express the variation within these families, concerning size, weight, and angle, for example.

If we forget for a moment that letters themselves convey meaning, these two levels of variation—choice of script and of its execution—comprise perhaps the greatest value to the historian of the medieval book: they show us when a manuscript was made. This information comes in extremely handy considering that the title page was not yet invented. But how does the script expert establish the precise date of production? Welcome to the illuminating world of handwritten letters from the Middle Ages.