What aspect of typography is most important for ensuring readability?

All aspects mentioned contribute significantly to readability in typography. Font choice and size are essential because they determine how easily the text can be recognized and understood. A font that is too small or intricate may strain the reader's eyes and lead to misunderstandings.

Letter spacing—also known as kerning—and line height, or leading, are crucial because they affect how text flows visually. Proper spacing helps prevent the letters from appearing too cramped or too far apart, ensuring that the words can be read smoothly without confusion. Adequate line height improves readability by providing enough room between lines, allowing readers to track their reading more easily.

Color saturation impacts the contrast between the text and the background. If the colors are too similar, the text can be difficult to read, especially for individuals with visual impairments. High contrast, preferably between dark text and a light background or vice versa, enhances visibility.

Since all these factors play a role in making text easy to read, it is correct that they collectively contribute to the overall readability of typography. Therefore, recognizing that each element is interrelated enriches the approach to effective typographic design.