Any grayscale mask can be reused. To do this, save the grayscale image as a flattened TIF or JPEG file. Later on, open the file and use image as a mask in other image. If the mask image is not the same orientation or size as the image you plan to use it with, choose Image>Rotate Canvas, 90 degrees CW to change its orientation. To change its size, choose Image>Image Size, click Window to open the menu and select the image to match size with and click Ok. To use the mask on your image, follow steps 4–8 above.