Penetrating Ink and Halftone Reflectance

摘要

A simple model of a halftone print consists of an ink layer on top of the paper. Light is transmitted through the ink layer on incidence, is reflected by the paper and is transmitted again through the ink layer on reflection. The transmittance is given by Beer's Law. For many types of paper, however, a more realistic model of the halftone process must include the effects of ink penetration into the paper. In this case, Beer's Law does not adequately describe the interaction of light with the ink because of scatter by the paper fibers. In the current work, the reflection and absorption of light is determined theoretically by solving the diffusion approximation to the radiative transfer equation for both the case of ink layer on top of the paper and the case of ink penetration into the paper.