2. Because the thickness is different, the strokes are different. Generally speaking, if the strokes are thick or complex in shape, the more things are represented, the more things are contained, the thinner the strokes are, or the simpler the structure is, the less things are represented.
3. Hard-pen calligraphy is much more widely used than soft-pen calligraphy, because hard-pen calligraphy is fast, easy to carry and easy to popularize at one time.