Restoring bench seats, whats good to replace matting?

I'm going to restore my Duster bench seats and wanted to know whats a good substitute for the matting they used originally? Some of mine is gone and exposed so I'd like to replace it. There is an excellent upholstery supply place here and they should have whatever would work. Thought I'd ask here first. Thanks ahead of time.

Tell ya what. My advise is don't substitute. Find a shop or a supply house that has the cotton batting like that's in there. I've had my front bench redone and the foams don't support as well and compress too much for that type of seat construction.

When I restored my 69 RR bench I used upholstery foam and its still pretty firm. I'll be headed to the upholstery store this week to see what I can come up with thats more correct.
Thanks for the reply

When I did the front seat of my (not mine anymore) '69 Bee, I used the cotton batting and instead of burlap, I used FLW cloth. The FLW cloth is strong, won't stretch, smooth on one side and rough on the other. If there is a Mosehart-Schleeter near you, that's where you can get the stuff.

As suggested, I got a big roll of the original style batting for $40 at the local upholstery supply store, a roll is enough for the front and rear seats. I got burlap at wally world for $11. The rear seats turned out perfect. The battings much more forgiving than foam and conforms to shapes much better. Easy to work with too. I will do the front seat this week.