I'm pretty sure you're able to do this but how can you preview a tattoo on a pony when it's a baby?
Well if you are making the tattoo fresh, you could always do a transparent layer over the pony's adult image using photoshop or something of the like, I use gimp myself. If you copy the tattoo and paste it as a transparent it should work the same way.
BdRyu the link isn't working
And Bunko I am doing that currently but I want to make sure the colours are solid when on the pony
I think it might have been because there was an Enter after the [url ] part. She linked to YayPepsi's guide:
There's also Cat's one: