Reading Letters Designing for Legibility This book will not only help type designers create high-legibility typefaces, but also help graphic designers determine the optimal typeface for a given project. Few of us will appreciate whether the typeface we read is legible, but we quickly notice if it is not. Creating type for optimal legibility is therefore an ungrateful task, since readers only register your failures. For instance, typefaces presented under difficult reading conditions, such as small font sizes in low-quality newspaper print, or street and building signs viewed from afar, need to be created in specific ways to function optimally.
designing for legibility Sofie Beier Reading Letters designing for legibility Copyright � 2011 Sofie Beier and BIS Publishers Text and design Typeface Publisher Sofie Beier Ovink bis Publishers Het Sieraad Postjesweg 1 1057 DT Amsterdam The Netherlands T (+) 31 (0)20 515 02 30 F (+) 31 (0)20 515 02 39 firstname.lastname@example.org www.bispublishers.nl ISBN 978-90-6369-271-1 All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopy, recording or any information storage and retrieval system, without permission in writing from the copyright owners. Reading Letters was partly funded by the Danish Centre for Design Research. Reading Letters designing for legibility bis Publishers SOFIE BEIER Contents Introduction � � � � � � � � � � � � � � � � � � � � 7 1. Test methods � � � � � � � � � � � � � � � � � � 9 Readers' preferences Continuous reading The search task Visual accuracy threshold 2. Understanding reading � � � � � � � � � � � 21 Letter identification Single letter and word superiority effects Word wholes Parts, wholes and context 3. Early approaches to legibility � � � � � � � 31 4. Theories on letter structure � � � � � � � � 37 Edward Johnston Gerrit Noordzij Frank E. Blokland 5. Stroke and contrast in history � � � � � � � 47 The Old Style stroke The Romain du Roi The Baskerville stroke The Didone stroke The Geometric stroke 6. The individual letter � � � � � � � � � � � � � 69 Internal letter relation Scientific results Designers' ideas Index � � � � � � � � � � � � � � � � � � � � � � � � 178 7. Type for text sizes � � � � � � � � � � � � � � 85 Block text Proportions M-formula Ink & printing Type for screen 15. The validation of legibility � � � � � � � 171 14. Familiarity in history � � � � � � � � � � � 155 Reading and writing in the Middle Ages Blackletter and Latin types The Civilit� type John Baskerville and his peers Didone and the French Revolution 10. Sans or serif? Scientific findings Familiarity of the sans serif 11. Hanging and ranging figures 12. The italic evolution The Cancelleresca italic The development of the Didone italic Cursive italic & sloped roman 13. Letter spacing � � � � � � � � � � � � � � � 149 � � � � � 131 � � � � � � � � � � � � � � � 123 Ideas in favour of the serif 9. The capitals � � � � � � � � � � � � � � � � � 113 Roman inscriptions Relative width Which is more legible? 8. Type at a romandistance � � � � � � � � � � 105 Compensation for loss of detail Proportions � � � � � � � � � � � 137 Acknowledgment Parts of the book are based on my PhD thesis `Typeface Legibility: towards defining familiarity', written while affiliated with the Royal College of Art, London, UK. Doing the development of the book, a number of people have kindly informed me on various aspects of their own expertise. In this regard I would like especially to thank Dan Reynolds for his helpful feedback on the final draft and for providing me with images of blackletter type. I would also like to thank Kevin Larson and Mary Dyson for general advice on scientific legibility research. I am very grateful for the input given by James Mosley enlightening me on historical matters, and for the help provided by Jan Middendorp pointing me towards useful typographical images. Furthermore, I would like to thank Chris Burke for putting me in contact with the Tschichold estate, Gerard Unger for providing drawings of Dwiggins' puppet, and Eric Kindel for the test material applied by The Graphic Information Research Unit. Last but not least, a big thanks to all the designers and foundries who so kindly have supplied me with images of their work. Without these, the book would never have been the same. Sofie Beier Introduction This book will, on the one hand, help type designers create highly legible typefaces and, on the other hand, help graphic designers determine the optimal typeface for a given project. Few of us will appreciate if the typeface we read is legible; however, we quickly notice if it is not. Creating type for optimal legibility is therefore a thankless task, since readers only register your failures. For instance, typefaces presented under difficult reading conditions, such as small point sizes in lowquality newspaper print or street and building signs viewed from afar, need to be created in specific ways to function at their very best. To understand the topic in depth, two very different areas of expertise have been consulted. One area is that of punchcutters and designers who, through their experience, possess useful knowledge that can help us better understand the various aspects of the matter; the other is that of academic reading research, where a significant amount of relevant scientific studies have been carried out over the years. Type designers have a subtle understanding for details and nuances that seem difficult to test in a laboratory, but many of the theories and ideas presented by designers do in fact lend themselves to laboratory testing. Some theories have already been verified, while others have been rejected. The outcome of this research has yet to be made widely available to designers. Consequently, many designers make assumptions without really knowing whether they are right or wrong. In a synergy between the two topics, this book will evaluate typeface legibility from different angles in an effort to provide useful information that can, hopefully, be transferred to practice. 7 Constituent parts of the letters shoulder ascender crossbar ear teardrop junction axis aperture arm spine eye cap height stem tail loop descender x-height Ttypographsce terminal contrast counter 1 Test methods Scientific studies on legibility-related matters have been carried out in a number of ways over the years. Many of the methods have been criticised for being insufficient. An argument often raised is that we must understand legibility fully before attempting to study it. One implication of this would be that all existing test methods are ineffective, since reading is such a complex process that no single method can ever produce sufficiently useful results. A common criticism is that a reader who is placed in a laboratory setting will always be aware of the action of reading, which means that obtaining a realistic measurement becomes problematic. The claim is that the human mind is too complicated for any valuable information to be extracted during a laboratory test. Whenever one aspect is tested, a range of other factors will inevitably influence the subject, and the experiment is bound to lead to inadequate findings. However, studies carried out in a natural environment allow for too many uncontrollable variables, while a laboratory setting, on the other hand, makes it easier to control and isolate the many correlating factors that play a role in everyday life. A central point of criticism that is voiced in the legibility debate is that different test methods produce different results. Legibility researcher Miles A. Tinker1 compared 10 typefaces in terms of visibility under reduced illumination, perceptibility at a distance, speed of reading, and the reader's opinion about the most legible type. In this study, he found little agreement between the results of the four test methods. In the measurement of reduced illumination, bolder types performed better than lighter ones, a finding that had much in common with the test of perceptibility at a distance. Tinker also found that the reader's opinion was less compatible with speed of reading than the two other aspects, and that readers in general judged types that 10 Legibility ranking (1 = best performance) Visibility under reduced illumination Perceptibility at a distance Speed of reading Readers' opinion of legibility Antique (illustrated with Bookman Old Style) 1 3 3 2 Cheltenham American Typewriter Cloister Black Bodoni Garamond Old Style (illustrated with Century Old Style) 2 2 8 1 3 1 9 6 4 10 10 10 5 7 4-5 3 6 6 1 5 7 4 4-5 4 Caslon Old Style Kabel Light Scotch Roman (illustrated with Adobe Caslon Pro) 8 5 6 8 9 9 7 9 10 8 2 7 Figure 1.1. Different test methods produce different results. The findings by Miles A. Tinker when he exposed the same typefaces to different test methods showed a large difference in performance1. The typefaces are illustrated with digital fonts that are similar in style to the metal types applied by Tinker. perform well in distance studies to be best for comfortable reading. Instead of viewing this as a setback for the prospects of scientific legibility investigation, one might view the different findings as an indication of something more useful. Comparisons such as these reveal that typeface legibility is not a universal issue, where one feature or set of features improve legibility in all reading conditions. In other words, the level of legibility for a given typeface is not constant but varies, depending on the situation in which it is observed. 11 Continuous reading Designers often argue that book typefaces should only be tested in running text, as this is, after all, how the type is going to be read. The issue is not, however, quite as straightforward as it may seem. Comparing two columns of text set in different typefaces raises a range of potential dilemmas. Leading and spacing in the text always interact with one another, an issue that is particularly evident when matching two designs of different x-height (Fig. 1.2). If the leading is kept constant, one of the two is likely to be at an advantage. If, on the other hand, the leading is adjusted to give the typefaces a visual similarity, one text might take up more space on the page than the other, which may introduce a bias. A common goal in studies of continuous reading is to measure reading speed. It may, however, be problematic to assume automatically that fast reading equals high legibility. Perhaps speed should not be the goal. Maybe when we read a highly legible text, the type will make us read with less effort rather than increasing the speed of reading. This notion is supported by a study2 that compared text with different margins; the study found that although the speed of reading was reduced when readers were exposed to the text with larger margin, they had a better understanding of the content under this condition. Another central criticism in relation to tests of reading speed is the frequent lack of significance in the measured time differences between the fonts tested. Unfortunately, this does not necessarily mean that there is no difference; more likely, the test method simply is not sensitive enough to detect any variation. To test continuous reading, there are several methods to choose from. One method is to look at oral reading. Here, the participant reads a text aloud, and the researcher records the number of errors or the time it took. A problem with this approach is that the situation is unnatural for most adults. It can be difficult to determine whether mistakes are based on errors of identification or errors of interpretation or memory. When reading aloud, we often use similar words or restructure the text to improve the flow; this does not mean that we actually decode the text that way. Another consideration is that oral reading leads to a higher frequency of fixations on the line of text, and that oral reading speed is about half that of silent reading3. Furthermore, because the eye is faster than the voice when we read aloud, only substantial performance differences will show up in the test results. 12 Figure 1.2. What leading can do to a text. Leading can post a challenge when comparing typefaces of different x-height. The optimal leading for a typeface with a small x-height is not always the same as the optimal leading value for one with a large x-height. Illustrated with the typefaces Brandon Grotesque by Hannes von D�hren, and DS Musee by Dino dos Santos, both set in 22 point size, with a line height of 22. Note the difference in the white areas. Brandon Grotesque, 22/22 DS Musee, 22/22 Beautiful printing is an educator, the same as is any art. The thoughts of an author take on added value by reason of it. The mind is always receptive in proportion as it is helped to comprehend the real meaning of the writer. Beautiful printing is an educator, the same as is any art. The thoughts of an author take on added value by reason of it. The mind is always receptive in proportion as it is helped to comprehend the real meaning of the writer. 13 Expert craftsmen magically produce a wonderful instrument, which reveals almost incredible improvement over everyday music producing machines. Based on the problems related to measuring oral reading, it might make sense to study silent reading instead. The challenge here is how to measure reading when others cannot hear it. One way around this challenge is to test for comprehension and check whether readers have understood the text that they read. This does, however, lead to a new range of issues that need to be addressed. How, for instance, can we ensure that participants all have the same degree of interest in the topic of the text? If they find the topic boring, will that influence their concentration, and will their comprehension suffer as a result? Will we in fact be testing the participants' intelligence or simply their experience of being in a test situation? Furthermore, it has been demonstrated that high-frequency words such as `the' are read faster than other three-letter words4, and that sentences in the active voice are recognised faster than sentences in the passive voice5. If the experiment involves comparing two different texts set in two different fonts, the level of high-frequency words and the structure of the individual texts are likely to influence the outcome of the study. Then again, if all participants are tested on all type conditions, and if the test material is counterbalanced between conditions, these issues should not cause problems. 14 Figure 1.3. Eye tracking. The measurement of eye movements during continuous reading can provide researchers with useful information on lengths and durations of saccades and fixations. Illustrated with the typeface Stella, designed by M�rio Feliciano. The search task Another possible approach is to measure readers' ability to locate specific words or letters in a text. Such methods were applied in studies carried out by the research unit working at the Royal College of Art 6 in the 1960s and 70s. Their reason for choosing this method was a dislike for testing the readers' comprehension, as they judged the comprehension method as being influenced by too many unaccountable variables that were not related to the visual properties of the text. The problem with the search task method, however, is that it is more closely related to scanning than to actual reading. In addition, since most reading situations do not allow us to know the exact words we are about to read, the method is not a very close approximation of real-life situations. When participants know what to look for, the interrelation between the process of reading the word, and the processes of reading the individual letter, is dominated more by the word process than is the case in more natural reading situations (see more in Chapter 3). That being said, the search task method is very useful for studying participants' ability to identify a target object located among other elements. 15 Figure 1.4. Search task test material. Test material applied by The Graphic Information Research Unit working at The Royal College of Art in the 1960s and 70s. Participants were asked to locate the words on the left in the text shown on the right. 16 Visual accuracy threshold In this approach, the focus is on letter and word identification, while comprehension is not a priority. Participants in tests based purely on perception tend to be unaffected by the awkwardness of the test situation. As we know, optometrists can make rather accurate vision measurements in laboratory settings. That is because word recognition occurs on an automatic level and is therefore unaffected by the surroundings. This is confirmed by the famous phenomenon discovered in 1935 by J. Ridley Stroop7. Asking participants to name the print colour when presented with words such as `Yellow' in a green colour and `Blue' in a red colour, Stroop demonstrated that most participants found this to be very difficult; thus, the study concluded that we recognise words even when it would help us to ignore them (Fig. 1.5). There are several methods for measuring visual accuracy; one way is to briefly expose the participant to the stimulus. After this rapid exposure, which is so short that the eye is unable to move from one fixation to another, the participant is asked to identify the presented material. Because of the single fixation, an obvious risk is that the test method might vary too much from a more regular reading situation. On the other hand, it can be argued that the difference is not that significant, since the eyes are relatively stable when fixating BLUE GREEN RED YELLOW 17 Figure 1.5. The Stroop effect. The task is to name the print colour of the word `Blue' when it is printed in red, or the ink colour of the word `Yellow' when printed in blue, etc. Illustrated with the typeface Ovink by Sofie Beier. Figure 1.6. Testing short exposure with a mask8. To control the time frame in which the image will appear, it is helpful to let the stimuli be followed by some form of mask consisting of random dots or lines. That will remove the afterimage from the retina. a a on a stimulus, both in short exposures and in normal reading situations. It thus seems reasonable to assume that the perceptual processes would be the same. Yet this may not always be the case. It appears that humans sometimes process the same information differently, depending on the task they set out to perform9. In the short-exposure method, the participant mentally prepares for the task of perceiving the material in one fixation. In normal reading, the fixation is a part of a larger process and is not treated as a specific task. However, the method is useful for studying the legibility of individual characters or words and for identifying specific features for further investigation. 18 ISBN 978-90-6369-271-1 Reading Letters is a book about typeface legibility. In our everyday life's we constantly encounter a diversity of reading matters, these being display types on traffic signage, printed text in novels, newspaper headlines, or ones own writing on a computer screen. All these conditions demand different considerations of the typefaces applied. In a straightforward manner, the book discusses these aspects by drawing on typography history, designers' ideas, and by reviewing available scientific data concerning the process of reading. Easily accessible, and heavily illustrated, this is a most have for any designer looking for guidance when choosing a typeface for a given project. Sofie Beier is a type designer, researcher and lecturer employed at the School of Design under The Royal Danish Academy of Fine Arts. She holds a PhD from the Royal College of Art in London, on the subject of typeface familiarity and its relation to legibility.