The importance of supporting a tactile graphic is paramount to ensure the reader's experience is enjoyable and successful. Without support the user has to make assumptions about what they are viewing. For instance if the user is not a braille reader or the image is untitled they won't even know what it is they are reading!
Suitable support enables independence for the reader. Since an image may be used unaccompanied, support should be provided in the most appropriate format i.e. either in braille, large print or audio.
To learn more about why supporting a blind reader of tactile images is so vital visit the pages about Verbal Descriptions and Navigation.