I needed to create a distressed border mask for a couple of images. I used the prompt; "oval black and white distressed border, black and white indian ink on white background" to generate several. The first image is the Midjourney image. I used Photoshop to create the second image to use as an alpha channel or asn an opacity mask. For the second image, I used the warp tool in Photoshop to create more of a rectangle shape using image 2, the circular mask. Sometimes I use Midjourney to create assets other than a final image. It can be great to great textures and opacity masks