The headliner cardstock came from Chevy Truck Classic Parts. They sell a kit that contains pieces for all of the roof sections. They have to be trimmed to correct size and dimension (which is a royal pain!). It turns out that the section with the cutout for the dome light in their Suburban kit actually fits the panel truck and not the Suburban (I discovered, as did they after I told them, that the Suburban and Panel dome lights are on opposite sides of the appropriate roof bow). Getting these panels to fit correctly was actually one of the more difficult and frustrating operations of the restoration--getting them cut to the perfect length and curvature to the sides, while trying to hold them overhead and into the roof bows was a real trial and really a job for 4 hands rather than two (I enlisted my wife, who was a good sport). Overall, it came out pretty well, though there are a couple small gaps and irregularities, which are detectable on close inspeciton.