This magic tattoo depicts the text "INT +1"

Tattoo Attunement. This tattoo is attuned when by the artist applies it to your skin. If your attunement to the tattoo ends, the tattoo reverts to an inert image and the "1" changes to a "0". The tattoo may be re-attuned by spending an hour tracing the images to re-familiarize yourself with the tattoo’s capabilities, changing the "0" back to a "1".

While this tattoo is attuned, your Intelligence ability score is temporarily increased by 1.

Notes: Bonus: Intelligence Score