Remove the cover of the book you are repairing, if it hasn't come off already.
Scrape loose pieces of prior adhesive or other particles from the spine, front and back of the book. This may vary depending on where the cover of the book is detached.
Cut any loose ends away from the binding area but be careful to not cut away any part of the book.
Put a thin layer of book adhesive onto the exposed spine and let dry on its side on wax paper. Place another piece of wax paper over the book and place a heavy book on top. This will help the book that is being repaired from moving and expanding during the drying process.
Measure the length of the spine of the exposed book. Cut a piece of tape to fit that measurement
Apply another coat of book adhesive to the exposed spine right before attaching the binder tape.
Place the sticky side of the binder tape onto the spine of the book. The stitches of the tape should flank each edge of the spine. Fold over the excess tape that's on the outside of the stitches to secure the book. If your book spine is 1 inch, you want 1-inch book tape, if it's 2 inches, you want 2-inch binder tape.
Use a bone folder to smooth the tape on all sides.
Tear off the protective cover of the binder tape to expose the other side of the adhesive. Place the cover tightly onto the adhesive to finish off the book.
Open the book and smooth the tape, again, onto the book cover.
Wipe off any excess adhesive that may be present and insert a piece of wax paper between the cover and the pages of the book.
Put a heavy book on top of the repaired book and let it dry completely before handling.