Blocking refers to applying metallic foils on covers or jackets for aesthetic effect or routine maintenance for hardback books’ spines.
Blocks in book publishing refer to sections of text set apart from the main text as distinct units, usually distinguished by changes to text alignment (centering or flush left) or the use of different typefaces, font size, or leading. Professional book designers use this term more specifically.
Blocks of text are frequently employed to set apart quotations, chapter headings, epigraphs, and other short pieces that should be separate from the main body of text. Sometimes, blocks of text will use different font sizes or typefaces to stand out from their surroundings; alternatively, they might be aligned differently than usual (center or flush left, for instance).
Leading, or the space between lines of text, can also help separate blocks of text from their surroundings. Professional book designers frequently add extra leading or line spacing between blocks to make them more readable.
Text blocks such as framing illustrations and photographs can also become decorations. Sometimes, a coalition of text fills a space on a page when beginning an odd-numbered chapter, such as when starting on page two instead of page three.
When adding blocks of text to your book, you should keep several things in mind when placing blocks of text. First, ensure it stands out clearly from other text sections and is easy to spot. Second, employ leading sparingly so the text block remains easy to read. Thirdly, don’t simply use blocks as filler on pages – use them only when necessary!