What are the three types of dope used for aircraft finishes?

The selection of clear dope, semi-pigmented dope, and pigmented dope as the three types of dope used for aircraft finishes is accurate due to the functional roles these finishes play in aircraft fabric covering.

Clear dope is primarily used as a sealing and protective coat that allows the underlying fabric to show through while providing some UV protection. This type of dope does not contain pigments, making it ideal for preserving the appearance of a colorful fabric underneath.

Semi-pigmented dope serves a dual purpose. It provides some color while still allowing a degree of translucence, which can enhance the visual depth of the fabric and provide partial UV protection. This type of dope is often utilized in applications where some color variation is desired, but maintaining the fabric's natural look is also important.

Pigmented dope, on the other hand, is used when full color coverage is desired. This type of dope contains pigments that provide an opaque finish, effectively hiding the fabric beneath while offering robust protection against the elements. Pigmented dope is particularly important for aesthetic reasons, as well as for enhancing durability and UV resistance.

The inclusion of these types ensures that aircraft can be finished in a way that caters to both aesthetics and functional durability,