  A mechanism for the localization of spatially periodic, self-organized
patterns in anisotropic media which requires systems extended in all three
spatial dimensions is presented: When the anisotropy axis is twisted the
pattern becomes localized in planes parallel to the anisotropy axis. An
analytic description of the effect is developed and used to interpret recent
experiments in the high-frequency regime of electroconvection by Bohatsch and
Stannarius [Phys. Rev. E {\bf 60}, 5591 (1999)]. The localization width is
found to be of the order of magnitude of the geometrical average of pattern
wavelength and the inverse twist.
