The Lensbaby Blank Aperture Kit is a set of 10 aperture disks that give you creative control over the shape of the spherical highlights in your Lensbaby photos. The kit contains 10 blank disks that you can cut into custom shapes. The disks fit into all the Lensbaby versions, except for the Original Lensbaby model.
By using these disks, points of light in out-of-focus areas of the photo take on the same shape as the center opening of the aperture disk. For instance, with a star-shaped aperture, points of light behind the subject will appear as glowing stars.