  The network formed by ridges in a straightened sheet of crumpled paper is
studied using a laser profilometer. Square sheets of paper were crumpled into
balls, unfolded and their height profile measured. From these profiles the
imposed ridges were extracted as networks. Nodes were defined as intersections
between ridges, and links as the various ridges connecting the nodes. Many
network and spatial properties have been investigated. The tail of the ridge
length distribution was found to follow a power-law whereas the shorter ridges
followed a log-normal distribution. The degree distribution was found to have
an exponentially decaying tail, and the degree correlation was found to be
disassortative. The facets created by the ridges and the Voronoi diagram formed
by the nodes have also been investigated.
