Legge Gordon E, Bigelow Charles A
Department of Psychology, University of Minnesota, Minneapolis, MN, USA.
J Vis. 2011 Aug 9;11(5):10.1167/11.5.8 8. doi: 10.1167/11.5.8.
The size and shape of printed symbols determine the legibility of text. In this paper, we focus on print size because of its crucial role in understanding reading performance and its significance in the history and contemporary practice of typography. We present evidence supporting the hypothesis that the distribution of print sizes in historical and contemporary publications falls within the psychophysically defined range of fluent print size--the range over which text can be read at maximum speed. The fluent range extends over a factor of 10 in angular print size (x-height) from approximately 0.2° to 2°. Assuming a standard reading distance of 40 cm (16 inches), the corresponding physical x-heights are 1.4 mm (4 points) and 14 mm (40 points). We provide new data on the distributions of print sizes in published books and newspapers and in typefounders' specimens, and consider factors influencing these distributions. We discuss theoretical concepts from vision science concerning visual size coding that help inform our understanding of historical and modern typographical practices. While economic, social, technological, and artistic factors influence type design and selection, we conclude that properties of human visual processing play a dominant role in constraining the distribution of print sizes in common use.
印刷符号的大小和形状决定了文本的易读性。在本文中，我们关注印刷字号，因为它在理解阅读表现方面起着关键作用，并且在排版的历史和当代实践中具有重要意义。我们提供证据支持以下假设：历史和当代出版物中印刷字号的分布落在心理物理学定义的流畅印刷字号范围内——即文本能够以最快速度阅读的字号范围。流畅范围在角向印刷字号（x高度）上跨越10倍，从约0.2°到2°。假设标准阅读距离为40厘米（16英寸），相应的实际x高度为1.4毫米（4点）和14毫米（40点）。我们提供了已出版书籍、报纸以及铸字厂样本中印刷字号分布的新数据，并考虑了影响这些分布的因素。我们讨论了视觉科学中关于视觉大小编码的理论概念，这些概念有助于我们理解历史和现代的排版实践。虽然经济、社会、技术和艺术因素会影响字体设计和选择，但我们得出结论，人类视觉处理的特性在限制常用印刷字号的分布方面起着主导作用。
