Which of the following is a primary use of turpentine in painting?

Turpentine is primarily used as a solvent in the painting industry, particularly for thinning oil-based paints. Its effective ability to dissolve resins and pigments makes it ideal for adjusting the consistency of oil paints, allowing for smoother application and improved adherence to surfaces. When painters need to create a desired viscosity for oil paints or clean brushes and tools, turpentine serves as an efficient and traditional option.

While turpentine might have some association with other processes within the painting realm, it is mainly recognized for its role in thinning, which is crucial for achieving various techniques and finishes. The other roles listed, such as serving as a coloring agent, binder, or sealant, are generally fulfilled by other materials or substances more specifically designed for those purposes.