xfprint4 and a2ps seems to do the work. I have three other packages on my system for printing which are: gnome-cups-manager cups-pdf cupsys-driver-gutenprint. I don't have a default Xubuntu system but I installed everything myself so this is all that I have installed to get Mousepad to print on my system. Make sure you choose the right settings under System > Printers > Your printer > Properties. I chose Local or detected printer and Detected printer : Gutenprint.
xfprint4 and a2ps seems to do the work. I have three other packages on my system for printing which are: gnome-cups-manager cups-pdf cupsys- driver- gutenprint. I don't have a default Xubuntu system but I installed everything myself so this is all that I have installed to get Mousepad to print on my system. Make sure you choose the right settings under System > Printers > Your printer > Properties. I chose Local or detected printer and Detected printer : Gutenprint.