What distinguishes double stroke letters in calligraphy?

Double stroke letters in calligraphy are characterized by being done in two or more pen strokes. This technique involves applying two separate movements of the pen to create the heavier appearance of certain strokes in the letterforms. The double stroke approach allows for greater variation in thickness, resulting in a more dynamic and visually interesting letter. It is essential in calligraphy to distinguish between the lighter and heavier parts of a letter, which can enhance the beauty of the script and provide an artistic flair.

In contrast, size, the application of a single stroke, and the use of italic styles do not define double stroke letters. The size of a letter does not inherently differentiate a double stroke from a single stroke; rather, it is the number of pen strokes that matters. Similarly, a single stroke would produce a more consistent line without the intentional variation that multiple strokes provide, which is fundamental to the double stroke technique. Italicization, while a style used in various forms of calligraphy, is not a requirement for double stroke letters, making the distinguishing factor clearly the technique of using multiple strokes.