Hello @gabrielatravels , good morning.
I inform you that in tattoo world we accept henna tattoos and any temporary tattoos, such as adhesive tattoos.
If the design lasts more than 2 days is a temporary tattoo and is accepted, this is in the update of community standards.
It's exciting to know that you have in mind to make a sleeve and you save for it, that's a story worthy to tell in the initiative.
We are waiting for you.
Oh, that's awesome to hear then! My temporary tattoes take somewhere between 2-4 weeks so that will make them fit into the challenge :)