We need to picture in the eye of our minds a lengthy piece of parchment rolled tightly around a stick (though perhaps with the stick removed). To keep the rolled‑up scroll closed, we might picture (as it were) something like strings around the scroll (in this case seven of them), with wax on the knot of each string (see on Revelation 5:1).
1 Now I watched when the Lamb opened one of the seven seals, and I heard one of the four living creatures say with a voice like thunder, “Come!”