abs headliner shell

Hello, I would like to know if anybody knows what thickness i should use
to make a one piece headliner out of abs plastic.
i want to be able to heat it and mold it to the shape i want with a heat gun. Ive read a few posts on several sites where it explains how to do it.
The only thing they didnt say was what thickness it was. I dont need it too flimsy just thin enough to mold to the shape i want.

thanks

Wayne

 

I was just doing a search and came across this post. I would also like information.

I'd like to do a headliner for my 52 Dodge truck and would like to be able to mold a piece for the roof and the section above the door and upper corners.