by ascending and descending elements of lowercase letters and enables reading the entire word without having to parse out each letter (for example, dog is easily distinguished from cat) and that becomes more influential on being able to read groups of words at a time. Regarding how people recognize words when they read, studies comparing Bouma recognition and parallel letter recognition have favored parallel letter recognition, which is widely accepted by cognitive psychologists. Some commonly agreed findings of legibility research include: Text set in lowercase is more legible than text set all in uppercase (capitals, all-caps), presumably because lowercase letter structures and word shapes are more distinctive. Extenders (ascenders, descenders, and other projecting parts) increase salience (prominence). Regular upright type (roman type) is more legible than italic type. Contrast, without dazzling brightness, also has been found to be important, with black on yellow/cream being most effective along with white on blue. Positive images (e.g., black on white) make handheld material easier to read than negative or reversed (e.g., white on black). Even this commonly accepted practice has some exceptions, however (for example, in some cases of disability, and designing the most effective signs for drivers). The upper portions of letters (ascenders) play a stronger part in the recognition process than the lower portions. Readability also may be compromised by letter-spacing, word spacing, or leading that is too tight or too loose. It may be improved when generous vertical space separates text lines, making it easier for the eye to distinguish one line from the next, or previous line. Poorly designed typefaces and those that are too tightly or loosely fitted also may be less legible. Underlining also may reduce readability by eliminating the recognition effect contributed by the descending elements of letters. Periodical publications, especially newspapers and magazines, use typographical elements to achieve an attractive, distinctive appearance, to aid readers in navigating the publication, and in some cases for dramatic effect. By formulating a style guide, a publication or periodical standardizes with a relatively small collection of typefaces, each used for specific elements within the publication, and makes consistent use of typefaces, case, type sizes, italic, boldface, colors, and other typographic features such as combining large and small capital letters together. Some publications, such as The Guardian and The Economist, go so far as to commission a type designer to create customized typefaces for their exclusive use. Different periodicals design