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SØKELYS PÅ TEKSTJUSTERING

Robert Bringhurst, Ari Rafaeli,
Olav Martin Kvern, The Thanh Han

Ulike vurderinger av bruken av varierende tegnbredder og tegnmellomrom i tekstjusteringen

Av Torbjørn Eng

For å gjøre seg opp en mening om bruk av «glyph scaling» og «letterspacing» i tekstjusteringen, er det opplysende hva sentrale aktører i den typografiske verden mener om dette. Disse autoritetene har motstridende oppfatninger.

«Tiny adjustments... creating a page of even color and texture»

Robert Bringhurst
The Elements of Typographic Style
Version 3.1. Hartley and Marks, Publishers. 2005.

Most of the type set in the past five hundred years is justified type, and most of it has been justified line by line. There are, however, better ways. Scribes justify text as they write, by introducing abbreviations and subtly altering the widths of letters. Gutenberg replicated the feat by cutting and casting a host of abbreviations and ligatures along with multiple versions of certain letters, differing modestly in width. In the early 1990s, Peter Karow and Hermann Zapf devised a means of doing much the same in the digital medium - and without relying on scribal abbreviations. (...)

Another thing computer software can do – because Karow taught it how – is justify text by making subtle alterations in the widths of letters.

Good justification is calculated paragraph by paragraph instead of line by line. And the best computer justification now relies on microscopic adjustments to the space between and within the letters as well as the space between the words. In this book, for example, the justification engine has been permitted to vary the intercharacter spacing by plus/minus 3% and to adjust the width of individual glyphs by plus/minus 2%. The bulk of the work is still done by adjusting the spaces between words, but there are more letters than spaces in these lines. Tiny adjustments to spaces within and between the letters therefore go a long way toward creating a page of even color and texture.

EN VIKTIG TEORETIKER
Robert Bringhursts bok «The Elements of Typographic Style» er i dag en viktig referanse for typografi-interesserte. Første utgave (1992) ble produsert med Ventura Publisher, andre utgave (1996) med QuarkXPress. I disse utgavene advarer han mot «letterspacing» av minuskler og endring av «letter widths». Men i bokas tredje utgave (2004 og 2005), som er produsert i Adobe InDesign, tar han selv i bruk disse effektene i tekstjusteringen.

«Regrettable... that such a distortion of letterforms is 'typographically acceptable'»

Ari Rafaeli
Book Typography
Oak Knoll Press and The British Library. 2005.

Adjustment of character-space – increasing or decreasing – by various methods to mitigate the excessive word-space which occurs when an inappropriate measure is used, or when hypenation is inadequately applied, is an expedient which has been practised since the early 1960s when second-generation filmsetting made it possible, but it has never been done to good effect. There seems lately to be a trend in this direction notwithstanding and automatic modification of character-space and also of character widths (to reduce hyphenation and render closer word-space) are featured in one of the newer but already very popular applications, Adobe InDesign.

(...)

... one should expect the option (altså glyph scaling, min kommentar) to cause a distortion of each character of an affected line of justified text and perhaps the characters of the preceding or following lines to also suffer distortions, though differently, as widening or condensing will occur according to the amount of word-space which wants either reducing or increasing. Only the slightest distortions, of course.

It is regrettable that the venerable designer of some of the best types of the twentieth century should say that such a distortion of letter-forms is 'typographically acceptable'. It may be argued that the distortions, because they are ever so slight, won't be noticed but that is not true: I can see them very well in Hermann Zapf's example.

GRUNDIG ARTIKKEL PÅ NETT
Ari Rafaelis bok inneholder kapitlet «The school of close spacing», som er meget relevant for mange aspekter ved tekstjustering. Kapitlet er tilgjengelig på internett:

http://www.oakknoll.com/
bookexcerpt.php?booknr=79445

«Glyph scaling is evil, unprofessional, and should be removed from InDesign»

Olav Kvern
Debatt på nettbaserte Adobe Forum desember 2007.

INNLEGG NR. 1:

Harbs wrote: «No one will ever notice a tiny bit of glyph scaling, and it can make a *huge* difference in spacing!»

I disagree completely. Whether one can consciously notice the squashing and stretching of characters or not, one can certainly «feel» the difference. Glyph scaling is evil, unprofessional and should be removed from InDesign.

If you can't solve spacing problems with word spacing and judicious use of hyphenation, then a rewrite is called for. I would rather letterspace than use glyph scaling – and I would rather die than use letterspacing.

INNLEGG NR. 2:

The question, though (even if «nobody will notice» – which I dispute) is: why take the chance? Other methods exist that do not distort the shapes of the characters. If the reader's eye is sensitive to variation in letter spacing – as seems to be shown by a variety of studies – then we can only assume that it's even more sensitive to variation in character shape.

(...)

There is no such thing as perfect spacing for any text. There is only the best one can do, given other considerations. (...)

Clearly, the ideal (for text in English, at least) is to set text flush left and use hypenation sparingly to keep the line lengths similar. Then you don't have to worry about the problems introduced by justification. There is nothing good about justification from the reader's point of view.

INDESIGN-GURU
Amerikaneren Olav Martin Kvern er medforfatter av den avbildede boka (og tilsvarende utgaver for versjon CS og CS3). Glyph scaling er forfatterne motstandere av: «Misbruk av muligheten for glyph scaling kan føre til åpenbare forskjeller i bokstavenes form fra linje til linje.» Også i en nettdebatt på Adobe Forum desember 2007 kom han med klare negative meldinger (utdrag til venstre). Olav Martin Kvern har mange års yrkeserfaring som typograf i USA, og er en mye brukt kapasitet på fagfeltet. (Olav Martin Kvern and David Blatner: Real World InDesign CS2. Peachpit Press.)

«Font expansion ... must be used with great care»

The Thanh Han
Micro-typographic extensions to the TeX typesetting system
Dissertation, Masaryk University Brno, Faculty of Informatics, October 2000.

The improvement of interword spacing depends on the expansion limits. On the other hand, too high expansion limits causes that the effect of font expansion to be visible and thus detracts from the appearance of the typeset text. Choosing expansion limits for a font is thus not trivial and must be done carefully so the effect of font expansion cannot be visible. My experiments have shown that it is safe to expand fonts within such a limit so the variance in character widths must not exceed +/- 2%.

(...)

Font expansion helps to improve interword spacing and thus uniform greyness of a typset text, but it must be used with great care. To draw general rules for its use is not easy, since people tend to value the quality of a typeset document differently. While top quality typographers seem to agree on aspects like optimal grayness and what kind of manipulations are permitted, the average desk top publisher is very tolerant in applying generous spacing and seemingly arbitrary stretching of glyphs and kerns to achieve his personal objectives. (...)

VIKTIG TEORETISK GRUNNLAG
The Thanh Hans imponerende avhandling beskriver først de hensynene som tas ved tekstjustering, før den vurderer de mikrotypografiske mulighetene i TeX, hz-programmet og InDesign. Font expansion (=glyph scaling) diskuteres grundig - hvordan den virker med ulike fontformater, muligheten for skalering av kun utvalgte tegn mm. Dokumentet erkjenner farene ved glyph scaling, men konkluderer med at det er en god ting.

http://www.pragma-ade.com/pdftex/thesis.pdf

English summary

Differing viewpoints on glyph scaling and letterspacing in justification of text are presented. (See full English version here.)

Publisert første gang 2007-05-15.

Sist oppdatert 2008-04-12.

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