Way back in sins of the savior they introduced the feat Inscribe Rune for the purpose of tattooing a Thasilonian Rune on the target.
More recently they introduced the Inscribe Magical Tattoo feat, which is broader in application....
So my question....is there any reason you could not use the Inscribe magical tattoo feat to inscribe a Thassilonian Rune ?
From IMT:
Tattoos may be inscribed on the following slots: belt, body, chest, feet, hands, head, neck, shoulder, ring (up to two), or wrist. They cannot be inscribed on armor, eye, headband, or shield slots.
TR creates a new slot type called rune. IMT doesn't include this type.