Catchwords
For example, consider the beginning pages of volume 1 of the Advertencias. In the bottom right corner of the left-hand page, you should see the string of letters "ber." If you move to the following page, notice that the first word is "ber" (actually the second half of the word |aber (saber, to know)). Since printers didn't number every page, this was an easy way to make sure that pages were properly set and aligned.
Catchwords are also a useful way to track print history. Though the goal is for every catchword to perfectly match the subsequent page, this is rarely the case. Consider for example the catchword associated with folio 115 from a copy of Volume 2 held by the Benson Latin American Collection. Here, the catchword (dem) is associated with the word (eodem). A relatively neutral mistake, the error in this case is caused by an error in typesetting: the letters "eo" were printed twice.
The frequent errors introduced into the catchwords, however, makes them a useful tool in attempting to understand the printing process underlying the production of a book like this one. When we systematically compare catchwords across exemplars, an inconsistency comes to light. In some copies of Volume 2, the first word of folio 304 (¶Pau) is associated with a matching catchword (¶Pau). This is seen, for example, in an exemplar held by the Benson Latin American Collection.
In other copies, however, the first word (¶Pau) is paired with a catchword reading fub. This is the case, for example, in an exemplar held at the Universidad de las Americas Puebla.
What does this discrepancy tell us? Nothing definitive. But in a comparison of catchwords across 17 exemplars, 10 used the catchword fub, while the remaining 7 had the more accurate ¶Pau. This means that at some point during production, type was reset, and the printers either corrected their error, or introduced a new one.
Why was the type reset? One possibility is that the book went through two or more print runs. If the the printers didn't have enough type for the entire book, or if they were working on multiple projects at once, they would have taken apart the frames after printing the book - or a segment of the book - in order to produce the next one. If they then found themselves printing the book again, they would have been forced to reset the type.
