Retroreflective article comprising a transparent base sheet and nacreous pigment coating, method for making such a base sheet, and method for making a forming master

A method for making a forming master, comprising:

• a) providing an initial master comprising a retroreflective sheeting, said sheeting comprising a monolayer of microspheres and a space coat bearing a metallic coating and covering said monolayer of microspheres, said metallic coating comprising a surface having a nonuniform array of substantially hemi-spheroidal protrusions of different heights thereon, said protrusions being wider at their bases than portions of true hemispherical protrusions of the same height;
• b) preparing a curable composition;
• c) depositing said composition onto said metallic coating in an amount at least sufficient to cover said protrusions;
• d) spreading a bead of said composition between a substrate film and an initial master, said substrate film being substantially planar, at least one of said initial master and said substrate film being flexible;
• e) curing said composition to yield a composite comprising said substrate film and said composition;
• and
• f) removing said composite from said initial master to yield said forming master.