Here you get an overview about materials and construction principles used in tennis string production.

Basic constructions Symbol Construction Example MONO Monofilament. The string is made of one single thick fiber, mostly with a surface coating. CW Solid central core (usually Polyamide) wrapped by one layer of thin filaments. Classic "tournament" construction, lowest price category. CWW Solid central core (usually Polyamide) wrapped by two layers of thin filaments. Classic "synthetic gut" construction. Increased elasticity compared to CW, but usually higher price. MF Multifilament construction. These strings consist of hundreds or thousands of microfilaments. Usually with one or more wrappings. Often polyurethane is used for impregnation. Depending on the material these strings provide great elasticity, but at a high price. RIB Ribbon construction. Inspired by the structure of natural gut strings, ribbons instead of filaments are used to make this kind of string. The benefit is increased tension stability. Additional features Symbol Construction Example S Structured or textured surface. Rough surface enhances spin through additional ball bite. TIC Titanium coating for increased resistance. TIF One or more Titanium fibers are incorporated into the string for increased durability and tension stability. Rare.   HYB Hybrid string. Different strings for mains and crosses. Usually a durable string for the mains and a resilient string for the crosses.