A method for tooling a pattern of retroreflective microcubes, which
pattern can be subdivided into smaller increments within which there are
straight line tooling paths, none of which pass through an otherwise
solid part of the incremental pattern. The tooling paths within the
various increments need not be parallel to a common plane. Various
adaptions of the method enable the tooling of a number of specific
microcube shapes and for modifying such optical properties of the
microcubes as entrance angularity, incidence angularity, orientation
angularity, observation angularity, percent active aperture and
retroreflectance. Specific techniques govern the pre-selection of cube
parameters such as cube axis cant, cube apex decentration, and cube
boundary proportions, which parameters can be adjusted independently of
each other. Designs tooled by the method can have 100% active aperture at
near zero degrees entrance angle. The method involves providing a
plurality of plates of micro thickness, each plate having at least one
end comprised of a material that can be tooled with polished surfaces by
means of an appropriate tool, tooling on said end of each plate an
increment of the pattern, and assembling the plates together in various
ways to form a master. Retroreflective articles made by means of this
technique are expected to provide superior performance when used in
pavement markers, highway signs and other applications.