Before publishers bound their publications, printers would do a simple preliminary stitch keeping the signatures together, and then cover the text block in wraps. When someone purchased a book from the printer they'd take it to their book binder to properly sew the text block and cover it, if they could afford to do so. Most books printed but not bound didn't last; it's special to find a rare book with its original wrappers nowadays.
This is an example of a printed pamphlet from 1835 that would have had wraps; instead of binding the pamphlet my client decided to have me make and add period appropriate wraps in keeping with the history of this little book. I then made a protective clamshell to house this special book.
Collect. Conserve. Restore. Become part of the history.