By doing this, it is creating a bit of a burr and a bit of a wire edge, and it is rolling the knife mettle over. So after repeating it for 30 or 40 times, you will notice that a thin wire edge is developing inside the scallops, but that’s perfectly fine. That’s what we are looking for.
Now if you check the other side, the side which was actually being rubbed on the rod, you will notice that there isn’t much of the metal taken off after this process, and you won’t see any scratch marks along the flat side, because the ceramic is harder than the steel, so it is also polishing the knife steel.
So as I said when applying the knife strokes backward, you are moving the metal down towards the primary cutting edge, and it will form a burr, what you can feel if you run down your fingers flat over the scallops.
What this means? This means that the steel side of the knife has moved towards the main cutting edge. So now we need to move the burr back for the serrations to be straight.
For that, you need corrugated cardboard.