headliner

I know next to nothing about headliners... bought my '72 Swinger (2-door hardtop) as a stripped rolling shell, stuffed with all the parts in boxes & bags. And a cardboard headliner that looks reusable.

I found this article on replacement vinyl liners with bows:
How To Replace Your Headliner On Your Dodge Dart - Mopar Muscle Magazine

Wondering what holds the cardboard liner up there - is it pointy barbs all the way around?
Oh man you got a good cardboard? The trim and the dome light the visors the front and rear window seals all hold the cardboard up.
Also pictures help. Why doesn't anybody show pictures?