Like just the honeycomb type material, I need a strip about 14" x maybe 4".

Unless one of you all has a better idea. Here's what I'm trying to do.

I have a Tilite ZRA and I am getting a new chair with the same specs as my old one (just a TRA this time to see what the box frame is about), and I like everything about it, except the posts of the backrest jab me in my ribs. I'm a six foot dude and my chair is 13" wide, which means the area between the back rest posts (currently set at 16" high) is maybe 11". Needless to say, my body including my ribs is wider than this. So I end up spending much of my day leaning forward on a desk or at home with a pillow stuffed between me and the backrest... But I don't want to change any of that. I like having a sling back and I like having the backrest at the current height.

What I'm trying to figure out if I can build is a little back pad to strap over the top of the chair. Really it's only purpose would be to cushion the top of the backrest posts where they jab into my sides, but pushing the top of the seatback forward a bit would provide some lumbar support too, which would be nice. So I'd like to have someone sew up a cushion that goes down about 3-4" from the top of the backrest and have some padding over the posts. I have a stimulite cushion and I like the honeycomb material it's made out of and was thinking maybe this would be a good material to work with... but I'm open to suggestions if you all can think of a better idea.