Patent ID: 7445347

Claim:
A retroreflective sheeting capable of reflecting a relatively high percentage of light that is incident normally and substantially normally non-retroreflectively at an approximately 45° angle and which is particularly adapted for effectively retroreflecting light under nighttime conditions, comprising: a substantially planar transparent sheet having a dense array of cube corners and a substrate, said cube corners being canted edge-more-parallel at an angle within about 1.5 degrees of 10n-9 degrees as calculated with n being the refractive index of the sheeting in the cube corners, wherein said cube corners are coated with reflective material, and said substrate has a thickness in a range of between about 0.75 and about 4.50 times a cube corner height H, wherein said cube corners are formed from a ruling of three sets of parallel vee-grooves that intersect such that each cube corner, when viewed in plan, is surrounded by a triangle or quasi-triangle formed by the roots of the vee-grooves.