I have not had any useful results scanning anything under about 10 mm at
1200 dpi. I suspect it is just a matter of resolution, although the fact
that the shell is 3-dimensional probably adds to the problem.
The rule of thumb is that you need 300 dpi (dots per inch = 25 mm) for a
decent print, 72 dpi for the Web or e-mail.
John Wolff
2640 Breezewood Dr.
Lancaster, PA 17601
717-569-6955