Factory Dash Speaker Grill Cover. -Material?

[BlackoutSteve]

The AIM shows a "cover" installed with tape to the underside of the dash panel to cover the speaker grill when no speakers were installed there.
See UPC1 B2 #9 -3903481 (and #10 -3839835)

I have plenty of the tape , but what type of material was this cover made of please? I don't expect to find a repro one and intend to make a replacement myself.
I can only assume is was of a cardboard type material and is black. Am I close? Any pics would be very helpful.

Thanks. 

[JohnZ]

Yup - it was stiff cardboard, with a dark color on the side that faces up.

[william]

Same stuff the rear window tray was made of. There is a pic of one on page 328 of John Hoopers 1969 Camaro book. [Jerry M probably just spit up his Fruit-Loops].

[BlackoutSteve]

Thanks for that.. Yep, I got that book. (..and Jerry's ones too  )

So, who is John Hooper? Is he someone who frequents any of the usual forums?
Sounds like he and Jerry may not agree on a few things huh?