Single-core single-layer fiber tennis string is the most popular nylon string section structure today - most "gut string" are single-core single-layer fiber structure. The biggest advantage of this kind of string is that the pounds are not easy to decay, and the "crisp" feel of hitting the ball is close to the natural gut string. The texture and thickness of nylon inner core and outer fiber will affect the hitting feeling and comfort of the tennis line.

Multi-fiber tennis string is a bundle of extremely fine synthetic fibers twisted together to form a string, and its structure is similar to natural gut string. The multi-strand structure of nylon is superior to the structure with inner core in terms of comfort of shock absorption when hitting the ball, and the ball feeling is similar to natural gut string. At the same time, because this kind of string is soft and comfortable when hitting, it is more suitable for players who have tennis elbow but can't afford natural gut string. However, like the natural gut string, this kind of string will cause damage to it when hitting the ball, and may also cause the tennis line to bifurcate, so its service life is between the natural gut string and the cored composite string.