Typefaces designed for reading in continuous text have to be rigorously tested for legibility and readability. Legibility is the degree to which the letters of an alphabet are recognisable. Readability is the extent to which text is desirable to read. This is influenced by its composition and arrangement; the medium of presentation; cultural factors; and environmental factors such as lighting levels. There are a number of micro-factors that exert an influence such as weight of type, definition of joining strokes, openness of counters, and x-height to capital height ratio. A typeface must be reproducible at various sizes and weights maintaining legibility and readability. Although printing technology has improved, when reproducing small sizes on cheap paper stock there is a tendency for the counters to fill in with excess ink and effect legibility.
Dr Rosemary Sassoon has researched into the characteristics of typefaces children find most helpful in aiding their reading of type. Through talking with her target audience of children she was able to evolve a typeface with and for them. Sassoon found that children particularly liked typefaces with a slight slant; a simple sans serif form; exit strokes from the letters on the baseline; clear open counters; and longer ascenders and descenders which accentuated the word shape. Words are recognised by their shape. Words set in lowercase are more recognisable than the rectangular shape of words set in capitals. The features of Sassoon Primary corresponded with good practice guidelines taught to children regarding legible handwriting.
In the early 1970s Adrian Frutiger was at work on the lettering for directional signage at the then new Charles de Gaulle Airport in Paris. He designed a humanist sans serif typeface entitled Roissy after the village where the airport was being constructed. To optimise readability Frutiger increased the ratio of the x-height to the capital height, this gave the type design a larger appearing size. In 1976 the typeface was adapted for typesetting and re-named after its creator.
Typefaces for telephone directories
Bell Centennial and the US telephone directory
Matthew Carter designed Bell Centennial between 1975-78 for use in the United States telephone directories. Telephone directories need to accommodate many names. Economy of space is a key issue. A compromise must be struck between a type size that will facilitate the space issue and yet remain both legible and readable in a small type size. Carter’s proposal was to reduce the width of the typeface but ‘pinch in’ the connecting strokes to increase legibility. The condensed form of Bell was trial tested set over four columns as opposed to the previous design of three columns per page. The re-design made a dramatic saving of space and as a consequence the amount of paper used. Legibility and readability was not sacrificed. The amount of information was the same but it took less space. This is a case where design is seemingly invisible but has a positive impact on conservation.
UK Yellow Pages
Design company Johnson Banks and type design specialists The Foundry were asked to improve the legibility of the typeface used in the Yellow Pages telephone directory. There was an additional consideration however, they had to fit more information into the same space. Telephone numbers were proliferating and as a consequence were getting longer. More numbers meant more lines of type so there was increasing pressure to conserve space both vertically and horizontally. The resulting typeface combined a condensed design; a decreased ascender and descender height of 75% normal design; and chiselled counters, junctions and exit strokes that allowed for ink spread. This resulted in more letters being able to be set horizontally and lines being set closer together vertically.
In 1964 as a response to the Geneva Protocol for the unification of road signage and in conjunction with the Worboys Committee, Margaret Calvert and Jock Kinnear embarked on a project to re-design the signage for the British motorway system. The system employed colour coding; a specially designed and spaced typeface entitled Transport; and a rationalised style for arrows and symbols. The typeface was tested for readability when travelling at speed when people have limited time to assimilate information. Further information can be found at Public Lettering.
Helvetica and Univers
Helvetica and Univers, both appearing in 1957, are important typefaces in the development of information design. They have a considered design that places the emphasis on simplicity of form and clarity of readability. The details of the letters are reduced to their essential form. Frutiger devised an ingenious numerical code for the 21 variants of the Univers family. This system replaced an often-baffling nomenclature of weights and widths.
The typeface Meta has been described as the ‘Helvetica of the nineties’. This is an indication that certain typefaces set the standards. Meta was conceived to satisfy a range of applications including poor quality printing on sub-standard paper in small sizes. The designer, Erik Spiekermann, had researched into more than 20 existing typefaces that had proven themselves under these difficult conditions. He took the best bits of each and combined them into Meta. The font incorporates pseudo-serifs and exaggerated features designed to increase legibility at small sizes. Although legibility is a big consideration Spiekermann has stated: ‘legibility is not communication; but in order to communicate type has to be legible’.