subway test
A test designed to simulate the distortion
imparted to a paperbound book by a reader holding
it in one hand with covers touching. The volume is
bent through 360° to bring its covers back to
back. If a leaf becomes detached, the volume fails
the test. In flattening a book in preparation for
use in most copying machines, a book also
undergoes a partial distortion, so that the subway
test, with its resultant stresses on the binding,
is valid, at least to a limited extent, in
determining the durability of the binding. The
test, nevertheless, is subjective and care must be
taken that it is conducted by the same trained
individual every time in order to avoid operators'
variables as much as possible. The name of the
test derives from the habit some (standing) public
transit riders have of holding the overhead strap
or bar with one hand while holding a book (usually
a paperback) in the other. See also: PAGE FLEX TEST .