ASA (acrylic styrene acrylonitrile) is a type of thermoplastic commonly used in 3D printing. It is known for its strength, rigidity, and resistance to UV light and weathering. ASA filaments are usually white or off-white in colour. However, they can be dyed or pigmented to produce other colours. ASA is typically used for applications with high strength and durability, such as automotive parts, outdoor signage, and industrial prototypes.