Photo Quality Printing on a Digital Press

In this paper, we will address the issues and the challenges for achieving photo-quality output with bi-level digital printing technologies. We will present the case study of transforming a 4-color Hewlett Packard Indigo liquid electrophotographic digital press, into a 6-color printer that can print images that are comparable, in terms of image quality and image permanence, to the traditional prints produced on silver halide photographic paper. We will discuss the requirements for gamut size, inks, color separation, halftoning and image permanence. We will describe the technologies and the methods needed to meet the requirements for photo-quality output.