The present invention features processes and compositions for producing a metallic-looking image on a substrate having a reflective or luminescent surface. The process utilizes an opaque coating composition containing an opaque coating agent comprising a mixture of a polyacid and a polybase. When applied to a light-emitting, reflective or luminescent substrate, the opaque coating composition at least partially masks the light-emitting reflective or luminescent surface of the substrate, but becomes increasingly translucent or transparent when contacted with a recording liquid such as an ink, revealing the light-emitting, reflective or luminescent surface.