due to narrow spacing. Another cause of rivers is the close repetition of a long word or similar words at regular intervals, such as "maximization" with "minimization" or "optimization".

Rivers occur because of a combination of the x-height of the typeface, the values assigned to the widths of various characters (whether the type appears broad or skinny), and the degree of control over character spacing and word spacing. Broader typefaces are more prone to exhibit rivers, as are the less sophisticated