An exposed lens retroreflective article (100), transfer articles comprising same, and methods of making same. The retroreflective article can include a binder layer (114); a layer of transparent microspheres (108) partially embedded in the binder layer; and reflective layer (110) disposed between the binder layer and the microspheres. The reflective layer (110) can include a dielectric mirror, which can include a first stack (115) and a second stack (111) positioned in planar contact with the first stack, wherein each of the first stack and the second stack comprises at least one bilayer (119), wherein each bilayer comprises a first material with a first bonding group and a second material with a complementary second bonding group. The transfer article can include the retroreflective article and a carrier web. The method can include partially embedding transparent microspheres in a carrier web; applying the reflective layer to the microspheres, and applying a binder layer composition to the reflective layer.

A light directing article comprises an acrylic polyvinyl acetal film to protect the optical elements of the light directing article. The acrylic polyvinyl acetal film has a Tg of at least 30° C. and comprises a (meth)acrylic polymer and polyvinyl acetal polymer. The acrylic polyvinyl acetal film is flexible and durable to mechanical deformation.

A retroreflective optical element is provided in which modified glass beads having a high refractive index are embedded on the surface of a thermoplastic core. The glass beads are heated to a temperature near the softening point of the thermoplastic core and the heated beads and thermoplastic cores are mixed in a fluidized bed. The beads embed into the thermoplastic core and are also chemically bonded thereto through a silane coupling agent provided on the beads.

A retroreflector includes a regular arrangement of multiple reflective triples of the first type, each having three side surfaces of the first type, which triples stand approximately perpendicular to one another, in pairs, and define a cube corner having an apex, at which the planes spanned by the three side surfaces of the first type intersect. A number of selected triples of the first type each have a recess, in particular a cube-shaped recess in the surface of the related cube corner and/or an elevation, in particular a cube-shaped elevation projecting from the surface of the related cube corner, which forms a triple of the second type, wherein the triples of the second type each have at least three side surfaces of the second type, which stand approximately perpendicular to one another, in pairs.

A retroreflector includes a regular arrangement of multiple reflective triples of the first type, each having three side surfaces of the first type, which triples stand approximately perpendicular to one another, in pairs, and define a cube corner having an apex, at which the planes spanned by the three side surfaces of the first type intersect. A number of selected triples of the first type each have a recess, in particular a cube-shaped recess in the surface of the related cube corner and/or an elevation, in particular a cube-shaped elevation projecting from the surface of the related cube corner, which forms a triple of the second type, wherein the triples of the second type each have at least three side surfaces of the second type, which stand approximately perpendicular to one another, in pairs.

A light directing article comprises an acrylic polyvinyl acetal film to protect the optical elements of the light directing article. The acrylic polyvinyl acetal film has a Tg of at least 30 C. and comprises a (meth)acrylic polymer and polyvinyl acetal polymer. The acrylic polyvinyl acetal film is flexible and durable to mechanical deformation.

Retroreflective articles include a layer of optical elements (110,120,130), embedded in a bead bond layer (140). The optical elements include transparent microspheres (110), at least one colored polymeric layer (120) covering the transparent microspheres, and a reflective layer (130) covering the colored polymeric layer. The polymeric layer includes at least one nanopigment. The transparent microspheres have a diameter range of 80-120 micrometers, with at least 75% of the transparent microspheres having a diameter range of 85-105 micrometers.

An exposed lens retroreflective article (100), transfer articles comprising same, and methods of making same. The retroreflective article can include a binder layer (114); a layer of transparent microspheres (108) partially embedded in the binder layer; and reflective layer (110) disposed between the binder layer and the microspheres. The reflective layer (110) can include a dielectric mirror, which can include a first stack (115) and a second stack (111) positioned in planar contact with the first stack, wherein each of the first stack and the second stack comprises at least one bilayer (119), wherein each bilayer comprises a first material with a first bonding group and a second material with a complementary second bonding group. The transfer article can include the retroreflective article and a carrier web. The method can include partially embedding transparent microspheres in a carrier web; applying the reflective layer to the microspheres, and applying a binder layer composition to the reflective layer.