Hola:
 
Using CorelDraw I have make an angle comparer that I find very useful to measure
spire angles; each comparer is 2x2 inches and is formed by a set of parallel
lines croseed by another set of parallel lines at a given angle; we see this in
the squared paper where the angle is 90:.
 
I have construct 12 comparers in the same piece of paper using angles 30, 35,
... 85:; you can put your shell in each of the equares and observe in which one
it addaps better; I heve test several shells, several cm., 15mm., 3mm (the last
one under the microscope) and it works.
 
I have printed the page at 360 dpi in normal paper and at 720 dpi in special
paper; the 720 is beautiful and the 360 is very usable.
 
 The file of CorelDraw (.cdr) occupies 11k; when I transform it to JPG it went
to more than 1 mega. I was thinking that not every one has Corel, but you can
find a friend who print it for you.
 
I can send a copy of the file in .cdr if you are interested in it; if .cdr is
not useful for you we can find another kind of file that I can produce and you
can receive.
 
Un saludo a todos
Emilio.