In book publishing, a block is a section of text that is set off from the main text as a distinct unit. It is usually identified by a change in text alignment, such as centering or flush left, or by the use of a different typeface, font size, or leading. In professional book design, the term refers to a more specific typographic convention.
Blocks of text are commonly used to set off quotations, chapter headings, epigraphs, and other short pieces of text that are best not integrated into the main body of text. In some cases, blocks of text are set in a different typeface or font size in order to make them stand out from the rest of the text. In other cases, the text is aligned differently, such as being centered or set flush left.
Leading, or the space between lines of text, is another way that blocks of text can be set off from the rest of the text. In professional book design, blocks of text are often set with extra leading, or line spacing, to make them more readable.
Blocks of text can also be used for decorative purposes, such as setting off illustrations or photographs. In some cases, a block of text is used to fill an empty space on a page, such as when a chapter begins on an odd-numbered page.
There are a few things to keep in mind when using blocks of text in your book. First, make sure the block of text is set off from the rest of the text in a way that is clear and easy to see. Second, use leading judiciously so that the block of text is easy to read. And finally, don’t use blocks of text simply to fill up space on a page—use them only when they’re truly needed.