Letter spacing may also refer to the insertion of fixed spaces, as was commonly done in hand-set metal type to achieve letter spacing. Due to deadlines, news editors do not usually have time to rewrite paragraphs that end in split words or create widows or orphans. Letter spacing adjustments are frequently employed in news design. Adding too much space, however, may isolate individual letters and make it harder for the reader to perceive whole words and phrases, reducing readability. Adding whitespace around the characters allows the individual characters to emerge and to be recognized more quickly. Tight letter spacing, especially in small text sizes, can diminish legibility. The amount of letter spacing in text affects legibility. Therefore, in QuarkXPress, a tracking setting of 3 reduces the visual density of the text noticeably, but in InDesign a tracking setting of 3 is barely noticeable. QuarkXPress uses units of 1/200 of an em, and Adobe InDesign uses 1/1000 of an em. In modern digital page-layout software, high-end applications all use relative measurements proportional to the size of the type. In the days of machine-implemented lead typesetting, such as Linotype machines and the Monotype System, letter spacing had to be uniform. Digital type does allow for negative sidebearings, which were uncommon in metal type because of the difficulty in cutting a " kern". Most systems have the default letter spacing at zero and instead use the character widths and kerning information built into the font itself.Īlthough digital type sets tighter than metal type on average, this results primarily from the availability of kerning. Word processing and desktop publishing programs for personal computers, such as Microsoft Word, Microsoft Publisher, WordPerfect, QuarkXPress, Adobe InDesign, Adobe FrameMaker, Adobe Illustrator, and Adobe Photoshop, use differing methods of adjusting letter spacing. Printer and type designer Frederic Goudy stated that "Men who would letterspace blackletter would shag sheep." Goudy's statement inspired the title of the book Stop Stealing Sheep, an introduction to typography.
It was also used for very short phrases set in capital letters or small caps to prevent the phrases from appearing too black compared to the rest of the page. Despite the cost, letter spacing was used in print advertising and book publishing. Letter spacing required hand insertion of copper (a half-point), brass (one point), and printer's "lead" (two points) spaces between individual pieces of type or between matrices. Some publishers and typesetters avoided letter spacing because it was costly in materials and labor. In the days of hot metal typesetting, letter spacing required adding horizontal space between letters of words set in metal type in increments of a minimum of a half-point. Tracking can similarly go in either direction, but with metal type, one could make groups of letters only farther apart (positive spacing). Digital kerning could go in either direction. A kern could therefore only bring letters closer together (negative spacing). Historically, with metal type, a kern meant having a letter stick out beyond the metal slug to which it was attached, or having part of the body of the slug cut off to allow letters to overlap.