In this paper we compare several patterns of clustered dots printed by an ink jet or an electrophotographic printers. It is important to discuss the shape of printed dots because dispersed dots and clustered dots produce the mid-tone images in the halftoning process. While a larger cluster is more stable in size and shape, some white areas surronded by certain patterns of clusters are affected by those clusters.
Shigeru Kitakubo, Yasushi Hoshino, Shi-Biao Xu, "Effect of Dot Clustering on Stability of Printed Image" in Proc. IS&T Int'l Conf. on Digital Printing Technologies (NIP19), 2003, pp 777 - 779, https://doi.org/10.2352/ISSN.2169-4451.2003.19.1.art00079_2