From the introduction:
In Paper Tigers, your party will roleplay a group of heroes who have been drawn into existence. They exist as 2-D figures in the 2-D worlds of our media. And while they exist on surfaces we have fashioned, in the manifold liminal spaces created by our media, they know us not.
Unlike the toys in Toy Story, these drawings cannot observe our world directly nor participate in it secretly when we are not looking. And yet, unlike the characters from Kingdom Hearts, these drawings do not have a storybook world of their own they can inhabit. They are caught in the surfaces between the two.
Like shadows, your mightily drawn heroes are beholden to the pages, walls, screens, and other surfaces of our world, where they move across, betwixt, over, and through them seamlessly.