Justification describes how lines of type are aligned on a page. Left-justified poetry usually preserves a ragged right edge, while fully justified setting adjusts word spacing so that both margins appear even. Because poems depend on line endings and white space, full justification can sometimes create distracting gaps or alter the visual character of short lines. Printers choose justification with attention to rhythm, readability, and the intended shape of the poem on the page.

Justification controls how lines align with page margins. Left-aligned text usually preserves natural word spacing, while full justification may create uneven gaps, sometimes called rivers, within the text.