Which feature is essential for achieving contrast in Gothic lettering?

Variations in weight are essential for achieving contrast in Gothic lettering because this style often relies on dramatic differences between thick and thin strokes. This variation creates visual interest and enhances readability, which are key characteristics of Gothic calligraphy. By emphasizing the thickness of certain lines while contrasting them with thinner strokes, the overall effect is a more dynamic and expressive letterform. This stark contrast is what helps to define the intricate designs associated with Gothic lettering, allowing each character to stand out.

In contrast to the other options, bold strokes alone do not provide the necessary interplay of light and shadow that offers depth. Thin lines can contribute to a delicate appearance, but without the necessary thick strokes to create contrast, they may lack impact. A uniform size would negate the essential elements of Gothic design, which flourishes on variation and complexity in its letters. Therefore, variations in weight are integral to the style and are critical for the visual identity of Gothic lettering.