Upholstery and Fabrics - redo chairs

I would like to take my old cane back chairs and replace the cane with fabric what do you use for the back support when the cane is removed and how do you put this in place of the cane so the chair is sturdy to lean back on the chairs are high back thanks devonne

I really don't know if there's a way to just replace the cane part. I would think you have to cut a thin piece of plywood the shape of the back of the chair, glue on upholstery foam, cover in batting, attach to the front of the chair and then make a slipcover for the whole chair.
If you could find a way to just add the plywood into the opening, I would think be the time you add the foam, batting and fabric (all needed to make the back sturdy and comfortable) it will be sticking out front and back and may look odd, not to mention uncomfortable.
Maybe someone else knows of a way?

I think you can remove the cane and upholster the back. It will now be a french back. Take off the cane so the wood is clean of all cane and glue. Make a french back like this, put a layer of fabric stabling the staples end to end all around with the good side of the fabric facing out. I don't know where you will find upholstery grade cardboard, maybe upholstery supply, cut the cardboard the shape of the back where the cane was. Staple the cardboard in place. Put a layer of cotton, then upholster the top layer of fabric putting the staples edge to edge. Finish with decorative gimp or double piping to cover the staples. Glue the trim with hot glue.