SATURN RINGS:
The A-ring ends at about 137'000 km from Saturn's centre.
Such a distance includes the major part of the luminous rings.
length = 137'000 km, thickness = 0.1 - 1 km (see source).
Ratio of 137'000 : 1
SHEET OF PAPER:
To easily estimate the thickness of one single sheet of A4 paper,
take
a block of 500 sheets: it has a thickness of about 5 cm, so
one
sheet is 5/500 = 0.01 cm thick.
length = 28 cm, thickness = 0.01 cm
Ratio of 28 : 0.01 = 2800 : 1
COMPARISON:
137'000 / 2800 = 48.9
Saturn rings are (proportionally speaking) about 50 times
thinner than a sheet of A4 paper!