Deutsch

legible & readable

Legibility is defined as “the property of a sequence of recognizable characters that enables these characters to be grasped in context”.1 Initially, the focus is on perceiving, recognizing and distinguishing individual letters and words. The micro-typographic influences that are decisive for this are explained in the character-related factors section.

In contrast, readability is the “property of legibly arranged sequences of characters that makes it possible to understand the information without doubt”2 . This refers to the comprehensibility of coherent texts, which in addition to linguistic form and person and situation-related influences, is influenced by typographic design. The macro-typographic influences that are decisive for this are explained in the section text-related factors.

The graphic shows the word ‘Handglove’ in a typeface representing the so-called Garalde style (Old Style). Dashed lines visualize the vertical dimensions of a typeface. The height of the middle zone of the lowercase letters is called the x-height. The upper parts of lower-case letters that extend beyond the x-height (e.g., in the case of d or l), are called ascenders. The dimension which contains these parts is called ascender height. The parts that extend below the baseline (e.g., in the case of g) are called descenders, the dimension which contains these parts is called descender depth. The sum of ascender height, x-height and descender depth, results in the type size. The height of the uppercase letters, also known as capitals, is called the capital height. Usually, the capitals are a bit smaller than the ascenders. The graphic also shows the thick vertical strokes, are called stems, and the finer horizontal strokes are called hairlines. White spaces within letters are called counters, the openings of the counters are called apertures. The nominal size for the width of the counters is called type width. The distance between the stems of two consecutive characters ‘n’ is called inter-character space. It is the nominal size for the spacing of a typeface. The protruding elements finishing off strokes are called serifs.

Legibility depends on the design of the dimensions and proportions of a typeface. These vary greatly depending on the form principle of the individual typeface.

Text genres

There is no typographic design that is equally suitable for all readers and areas of application. Typographic decisions depend largely on the content, purpose, and medium of a piece of information. Various genres of texts3 differentiate the respective requirements for the design:

Body text is continuous text that is intended to be read comfortably.

Consultation text explains or supplements body text, e.g. in captions.

Display text refers to headlines and accentuations that serve to design and structure texts.

Signage text is used for orientation in public spaces, e.g. in wayfinding systems.

  1. Body text is continuous text that is intended to be read comfortably, e.g. in books, magazines, instruction manuals and correspondence or on display panels.
  2. Consultation text explains or supplements body text, e.g. in marginalia, footnotes, lists, captions, or keys, and can be set at smaller sizes than reading text.
  3. Display text refers to headlines and accentuations that serve to design and structure texts, e.g. in magazines, advertisements or on posters, and for which no separate specifications apply - except for a larger type size.
  4. Signage text is used for orientation in public spaces, e.g. in wayfinding systems, and must be readable even from great distances and in different lighting situations and viewing angles. Due to these situational influences, the highest demands are placed on legibility here.

In the following, different typographical recommendations are given depending on the type of text. If no differentiation is made, the information applies to all text types. In some cases, the specifications for the visually impaired differ from those for the normally sighted, as higher requirements apply here.

Footnotes

  1. ↑ DIN 1450
    Lettering – Legibility
    April 2013 edition
  2. ↑ DIN 1450
    Lettering – Legibility
    April 2013 edition
  3. ↑ DIN 1450
    Lettering – Legibility
    April 2013 edition