You speak, think or write up to 25 words. Whatever you write appears as symbols within the Tattoos of the Ink Cursed you designate. These symbols are abstracted and only readable by the Ink Cursed who is the target of this spell. As an action the target of the spell can animate the message so in such a way that it can be seen by nearby creatures. 

The message stays on the body but shrinks to a small dot on a part of the body the target chooses. The message can be replayed anytime.

If the target of the spell is on another plane there is a 5% chance that it doesn't send. If it fails to send the message sits waiting on the plane until the recipient enters that plane, at which point the message sends. 

You can reply in the same way. 

A creature with truesight can read the hidden message.