Interior Impression Flaming....

I kinda didn't know what to properly make the topic but anyway. My question what did most of you use to do flame impression on your door panels...or anything else? Some sort of hard foam you need an electric knife to trip or what? Because when I do all my interior work in the spring I want to have everything ready and not have me still getting shit ready and making people wait. I am doing ALOT of flaming if I can but if not something else.

Thanks in advance!