[drMerry]

Thank you kovid.
I'm aware of that option.
The images are small enough for most (every?) e-reader.
While the lines between the cells are very small, every re-size would cause the picture to be less usable.
That is why I would like to be able to keep the original file regardless of the profile set. Is that possible?
I did see that the file was displayed all right if I did set it as cover, but in that case I'm not able to implement more than one sudoku a time.