Strength-to-weight – Composites typically have a significantly higher strength-to-weight ratio than traditional materials such as wood, metal and plastic.
Design flexibility – Composites can be formed into comples shapes and geometries just as easily as simple forms, often in one-piece, and can be finished in a variety of different ways.
Manufacturability – Composites come in a variety of sizes and thicknesses and  are generally easy to work with. They can be formed close to the final shape of the object so require minimal forming or finishing compared to a material like metal.
Versatility – There are many different composite materials, each with their own properties and characteristics. What’s more, relatively minor changes in the raw materials used or in the manufacturing process can change how the composite behaves and its potential applications.
Insulators – Many composites don't conduct heat or cold which makes them ideal for fire and blast protection and sub-zero applications.
Durability– Most composites are resistant to water, chemicals and other forms of corrosion which makes them ideal for use in outdoor or harsh environments.
Isotropic – Composites don’t have grain so won’t split, unlike wood.