Question: backing for pleats in vinyl for my Ford

[Bob]

Question:
I want to do some hidden stitch pleats for my 46 Ford seats. I tried using muslin backing but it is too soft and moves too much. I'm pleating the back as much as the vinyl.
Could I use fabric stabilizer for the backing under the foam strips? I won't glue it. Or is there something better out there? I have the vinyl and 1/2 foam but need a better backing. Something that wants to stay flat with out excessive bulk.
Appreciate your comments.
Bob

[MinUph]

You want to use sewfoam. It is 1/4" or 1/2" thick with fabric glued on the back already. Use the oink kind as it is firmer.

[baileyuph]

Do it like OEM has done after that period of time - buy the preformed foam .  Of course, the 48 didn't use
foam at all.  Cotton was the medium back then.  But later years  mfg's used the preformed.
But even then, expensive latex was the medium.

To win the international shows, as close to originality will win.

Doyle