A question about tilesets

Is it allowed to make tilesets designed to work as a small addion to a tileset? I want to make wings for Ripen's pirate ship tileset so I can make sky pirate ships. The wings would be a separate tileset, not an edit of current tiles.

well, I'd say yeah, after all it'd be your own work mostly, just inspired by the other one. But it'd be quite nonsensical to make your addon-tileset and not use the one it's adding on to, so I guess you are going to use Ripen's tileset. Which of course required proper crediting!

I would of course credit him. I'm probably going to end up making them a CO anyway, but I will state in the credits of the level what it was intended for.