Since version 2016.06.19 we have added several new papers for you to play with:
You can zoom in to see the amazing details:
Existing users would need to do a Factory Reset to the Paper Presets in order for the new default papers to appear, as illustrated in the figure.
Update: If the above doesn't work for you, try going to Start Menu>Expresii>Factory Reset, which resets the whole app (close Expresii before doing this reset).
Enjoy the new papers and let us know what you think!