Hi,
first of all thank you for the warm welcome.
Yes, sfm suggestion worked right for me 
thanks a lot!!!!!!!
Well I'm explaining why I need 400 images of the same stamps.
The stamp I'm trying to study was printed in 1850.
A sheet containes 240 stamps and so it containes 240 cliches of the "same stamp".
Each cliche' was created from a base cliche'.
The duplication process was not perfect so each cliche' has a flaw that distinguish it.
My aim is to catalogate the various flaws of the cliches which are extimated to be in total of 400 by experts.
The picture I attach will show you some flaws that can be found on a cliche',
an image is better than other words... 
The catalogation I will do is to draw manually each flaw as the one you see in my image.
I will draw them on a separate layer, the main layer is common to all stamps and is the stamp itself.
Thanks again!
I will be back with other questions, that's for sure!!!
pippo
