What characterizes a flourish in calligraphy?

In calligraphy, a flourish is defined as a decorative stroke that enhances the aesthetic appeal of letters, particularly at the open ends of capital letters. This embellishment is often characterized by elegant curves, loops, and swirls, adding a personal and artistic touch to the lettering. Flourishes serve not only to beautify the writing but can also contribute to the overall composition of the work, making it more visually engaging.

The other choices do not accurately reflect what a flourish is in the context of calligraphy. While paper, spacing, and ink are crucial elements in the practice of calligraphy, they play different roles. The type of paper used affects the texture and appearance of writing, spacing pertains to the arrangement of letters, and ink is essential for the writing process itself. None of these options embody the concept of flourish, which specifically pertains to the decorative enhancements applied to the letters.