If your talking about flat headliner boards in old trucks I usually use 1/8" abs

looking for something to use to make headliners for 4 door trucks that have some curve to it. We use a lot of abs when we manufacture our own parts and i dont feel that would work for the shaping of the roof

Gotcha. In my experience when doing custom shaped headliners people use a lot of different materials to get the result they are looking for. Fiberglass, wood and chip board, metal, ect. really just depends on what materials you are most comfortable with using.

Here is a good how to article that might help. http://www.how-to-build-hotrods.com/headliner-installation.html

Also there is a really good section on this in Ron Mangus's book called Custom Auto Interiors. Great book I highly recommend it. https://amzn.to/3qztUi0

hope this helps!

i just ordered the hardcopy off amazon thank you. Any tips and tricks help with out work. Some things have certain processes and concepts. Some are just your own creative ways and tips and tricks. The more knowledge the better

I couldn't agree more! That's why enjoy upholstery so much.