Illustrated Glossary: Bronzing

Bronzing is the widely known phenomenon of printed inkjet inks reflecting unintended and undesirable colors when viewed under specular light. This effect is most commonly found in black pigment inks; though, it has also been seen with other pigment ink colors as well as some dyes. It is most noticeable on semi-gloss and glossy papers and is due to a buildup of ink above the paper’s surface. In the examples below, under diffuse illumination, the printed ink appears grey as expected; however, with specular reflection, it appears bronze. Over time, manufacturers have modified and improved ink formulations and printing processes to minimize the effect, so newer prints are less likely to show the defect.