He wads up a sheet of toilet paper and holds it to the cut.

NEWYORKER: Midnight in Dostoevsky

Each enormous block is perfectly cut, polished smooth and fitted so tight not a sheet of paper would slip between them.

BBC: The perfect trip: Egypt

The hour and minute domes underneath are cut from solid aluminum to a thinness of just 0.28mm (a sheet of paper is about 0.1mm thick).

FORBES: Limited Edition: The $92,000 MB&F Frog Watch