Sponges are primarily used for which application in makeup?

Sponges are primarily utilized for blending foundation, concealer, and powder due to their unique texture and ability to create a seamless finish. When using a sponge, especially one that is dampened, it allows for the even distribution of product across the skin without leaving streaks or harsh lines. The porous surface of the sponge helps to absorb excess product while still letting enough color transfer onto the skin, which is essential for achieving a natural look. This technique is especially valuable for foundation and concealer application, where a smooth and blended appearance is crucial. Additionally, sponges can be used to soften the edges of makeup, making them an indispensable tool in a makeup artist's kit.

While sponges can be used for applying blush or setting spray, those applications do not fully leverage the blending capabilities that sponges provide for foundation and concealer. Similarly, while they can assist with contouring, the primary strength of a sponge is in its blending ability for base makeup products.