hi guys thanks for the suggestions i am actually using evergreen strip styrene i cut them to the width i want then use fibreglass duct tape and tape them all together so its flexible .the strip size that i want to use for the door is the #169 and the size is.080 x.250" (2.0mmx6.3mm) thats what it says on the package the thickness of the styrene is 2.0 mm so i guess the track opening will have to be slightly wider than that so it will slide up and down