How far apart should lines of text be according to calligraphy standards?

In calligraphy, the spacing between lines of text, also known as leading, is essential for readability and aesthetic appeal. The standard practice of five and a half pen widths provides a balance between allowing enough space for the ascenders and descenders of letters while maintaining a cohesive look to the text. This distance helps ensure that the text does not feel cramped and allows for a comfortable flow of reading.

When lines of text are placed too close together, as might happen with options suggesting fewer pen widths, it can cause the elements of letters to interfere with one another, leading to decreased legibility. Conversely, too much space can break the visual unity of the text, making it seem disjointed. Therefore, the selection of five and a half pen widths as the ideal spacing promotes an optimal reading experience while paying homage to classical calligraphic traditions.