Review on Enhance Upholstery Elegantly: GREEN FABWOOD Twisty Pins 50/pkg for Slipcovers, Bedskirts, and More by Jamie Denison

Headliner sagged so severely that the entire rear window was blocked. I tried Scotch 77 but it didn't work and left dark stains on the headliner material which you can see in the photos at the top corners of the rear window (and a few other stains). But the pins worked great, and since there were 50 in the small pack, there were more than enough. They were a bit too long as most were just under 1/2 inch, but they were easy to tighten with needle nose pliers and only took a few minutes. squeeze a dozen of them. I took a before and after picture of one of the pins so you can see the difference. In the [slightly blurry] before image, the pin size is about 7/16" and in the after image, the same pin has been compressed by just under 1/4". The pins are sharp enough to easily go through the headliner, but it takes a little work to get them to pierce and grab the material you want to attach the headliner to.There are actually 2 layers between the roof and the headliner.There is a thin foam-like sponge that the ceiling is glued from the factory, and on top of that layer of foam is a more durable material (like a thin piece of laminated cardboard) I'm not sure what it is, but it's what the pins have to go through to get the To attach headliner to the roof of the car It takes a bit of fiddling to get the pins to pierce but it's not that difficult and once it's pierced you just screw them all the way in and then move on to the next pin. it has who Took me less than 15 minutes to fix my sagging headliner with pins so I'm very pleased. Hopefully this will help deter anyone from getting the same type of studs specifically labeled as headliner mounts and ridiculously overpriced for only 8 or 12 studs.