  Structure of the intermediate state in type-I superconducting lead (Pb) is
shown to be very sensitive to the ramp rate of an applied magnetic field. The
configurations of resulting static patterns depend sensitively on the shape of
the specimen. In particular, geometric barrier, present in the samples with
rectangular cross-section, plays an important role in determining the sharp
boundary between the phases of different topology. We propose that seemingly
laminar (stripe) pattern obtained as a result of the fast field ramp is simply
an imprint left behind by the fast-moving flux tubes. Our results confirm that
flux tube phase is topologically favorable.
