No, it is not recommended to use an eyeshadow brush as a foundation brush. Eyeshadow brushes are typically much smaller and more densely packed with bristles, which make them suitable for applying eyeshadow precisely to small eye areas. Foundation brushes, on the other hand, are typically larger and have softer, more loosely packed bristles designed to apply foundation evenly across the face.

Using an eyeshadow brush to apply foundation can result in a streaky and uneven application, as the brush is not designed to distribute the product evenly over a larger area. Additionally, the small size of the brush may make it difficult to blend the foundation seamlessly into the skin, which can create a patchy and unnatural finish.

To achieve the desired result, it is recommended to use the appropriate brush for each step in your makeup routine. If you don’t have a foundation brush, you can use a beauty sponge or your finger to apply foundation, as this helps blend the product evenly into the skin.