well i finally sewed my bench pad cover today. I got some fairly stiff decorator fabric. used a 24 inch zipper on one long side. mistake! the foam pad wouldn't slide inside easily at all. i finally had to cut the foam in two sections. stuff each section in and then make the cut ends meet.
that is green foam and it doesn't bend easily. it's getting old so next year i will buy new foam and maybe make a slip case for it out of some slinky fabric to help it slide inside the cover next time. I'm just glad it is done.