When in the light, only the dotted outline of Akari and the "\Akkari~n/" disappearance spell will be fully visible, capturing her lack of presence.
However using glow in the dark ink, Akari reveals herself as she glows when the shirt is brought into the dark, having an actual presence.
The shirts are white and will be first available at the YuruYuri Nanamori Recital event on October 30th. They will go on general sale in early December 2011 for 2900 yen tax out (~$37.50 USD).
Image ©Namori/Ichijinsha, Nanamori-chuu Gorakubu