This report summarizes the results of more than 10,000 individual judgments, carried out in five related studies, all concerned with perceived reading efforts of text on visual displays and printouts. Students and personnel in the Department of Computer Science at the University of Stockholm served as study subjects. In experiments in which stimulus materials were real texts with similar context (lists of names and addresses), subjects were shown stimuli at random and were asked to judge their perceived reading efforts according to a five grade verbal rating scale: very great effort, great effort, neither great nor little effort, little effort, and very little effort. Methods and results of the five studies are presented in three categories: color of text and background; context colors; and printouts (from eight different printers). Five tables and a four-item bibliography support this report. (THC)