Paper has been developed primarily with modern GTK3 (GNOME-based) desktop environments in mind, legacy-toolkit and GTK2 environments will not provide an ideal experience, as much of the visual design relies on modern GTK3+ widgets.
You can download the Paper [here](https://github.com/snwh/paper-gtk-theme/archive/master.zip) or it clone from the [git repository](https://github.com/snwh/paper-gtk-theme).