The nib can be said to be the most critical part of the pen, which varies from fine to thick. Generally, the most common nib sizes are "B, M, F, EF", and from coarse to fine, it is B > M>F & gtEF. There will be some differences in the specifications of nib sizes for each pen manufacturer. Under the same size unit, the Japanese pen will be thinner than the European pen. According to the usual writing habits, Westerners usually use M-tip as the main pen and choose B-tip when signing. Due to the complexity of Chinese writing strokes, M, F or thinner EF pen tips can generally be used.