You are asking 2 different questions.
1)is how to modify the Jacket
Calibre has a brilliant system for users to have overrides.
If it sees a needed resource in the USERS configuration, that takes priority.
so place a copy of
Code:
C:\Program Files\Calibre2\app\resources\jacket
into
Code:
C:\Users\thedu\AppData\Roaming\calibre\resources
Note: This does not get updated when calibre does
This is where yo2 modify your 'jacket' look
2)file save template (THIS DOES NOT AFFECT THE LIBRARY. That can not be changed (See the FAQ Help)