A stretcher for substantially uniaxially orienting a film includes a
plurality of gripping members to hold opposing edge portions of the film,
paths along which the gripping members travel to stretch the film in a
stretching region, and a drive mechanism to convey the film and gripping
members along a machine direction. At least a portion of the paths in the
stretching region define diverging, curvilinear courses disposed
in-plane. The paths are configured such that during the stretching an
extent of uniaxial character, U, is between zero and unity and a minimum
value of an extent of uniaxial character, U, is at least 0.70 over a
final portion of the stretching after achieving a TDDR of 2.5. U is
defined as U=(1/MDDR-1)/(TDDR.sup.1/2-1), wherein TDDR is greater than 4
at an end of the stretching region.