Principles of aesthetic design for printed instructional materials are discussed in this paper, and a checklist is provided to aid in evaluating the aesthetics of such materials. The principles that are discussed relate to the following areas: format (spatial arrangement of a page and design principles involving simplicity, unity, emphasis, balance, and proportion), typography (legibility, type faces, and type size), illustrations, color, and graphs and tables. The checklist provides space for indicating the presence or absence of 45 features related to layout, type, color, graphs and tables, and illustrations. Also included are a selected bibliography of relevant works and illustrations of a few of the principles discussed. (GW)