An even number of gliders are attached with cord to create 8cm equidistant ripple pleats. If you are making the curtains allow approx. 2 times fullness and source your own header tape and hooks. The ripple cord will be supplied in one piece for up to 240cm poles, so simply cut the cord in half if you have a pair of curtains.
Add a minimum of 15cm either side, preferably more, but for full curtains or wide windows allow at least 25cm if you have the room, excluding finials (decorative pole ends).