The Location of Plates in a Book
When consulting a book with plates (that is, inserted leaves printed separately from the text), it is best not to assume that they have been placed in the same location in all copies of the same edition nor that their location in the book reflects the one intended by the author or the publisher. By contrast, the engravings in the Frankfurt editions of this book from 1604 and 1617 were printed on separate sheets from the text and their order and placement vary from one extant copy to another. Printing images with text, like in the Paris edition of Errard’s treatise, avoided having to select their location or to ‘misbind’ them in a book; but printing intaglio images with text could be difficult and time consuming.
Source: collation.folger.edu