Need to find a shirring tape

[jackieh]

I am recovering chairs by Hon.  They have used a nylon tape with a pull cord on the unfinished edges.  This then fits over the seat and the cord is pulled to fit the cover and a few staples to secure the cord.  Does anyone know where I can purchase this tape.  Cannot use the type for draperies as it is not heavy enough.  Also I cannot staple the fabric as the seats are mostly a molded plastic and will not hold a staple.  Any help would be appreciated as I do not want to use a seam ripper to remove all of the tapes to resew on the new fabric.

Thanks
Jackie