The diagram showing where to smudge the disc looks so incredible, a kind of flower shape, no rotational origin. Seeing the video it makes more sense. All this is highly artisanal, the diagram is just a hint.
This give me an idea. Here's my smudge pattern that works better: (shows a diagram with blotches in the shape of Rick Astley singing).
This give me an idea. Here's my smudge pattern that works better: (shows a diagram with blotches in the shape of Rick Astley singing).