Anita, the inner matte is the extension of the canvas and letting the radial blur drift outside the image area. I put my normal Blk and Wht edge on the image, before doing the radial blur, which gave the broken edge effect. I always extend the canvas to help center the radial point in the image. Then I cropped it, prior to the final framing, to fit the desired effect. Some of the effect of the inner matte is due to the processes of the following steps, as the radial blur was one of the first steps of the image.
It was one of the whole nine yard effects of this image!
