What to call a correction slip pasted onto a page of a book?

Solution 1:

Perhaps the term you are looking for is "cancel slip." I have found only two sources that describe such corrections:

The Bauman Rare Books glossary notes that a cancel may refer to either an entire page that has been replaced, or to "slip of paper pasted over the changed passage," noting that the latter may also be called a "cancel slip."

The Collation, in an article on cancel slips, shows examples of both large sections of text and small pieces of text being pasted over the original printed material.

Interestingly, the University of Saskatchewan has posted a fascinating article on the history of corrections in written documents, and if you scroll down to the section "Corrections in Print," you will find that they describe this process simply as "pasting over the text," reserving the term "cancel" for "a new leaf or sheet that has been printed to replace a section of the text containing errors." It seems that the term "cancel slip" is not in wide circulation, even among those studying historical printing.