We are often asked how to curtain a bay window. In reality you can use any of the standard curtains types, pencil pleat, pinch pleat, ring top and tab top. The problem is more about the track or pole that you use to hang the curtains. There are a few options available the first and more expensive option is to get a metal track or pole made to the size and shape of the bay. This would involve a track fitter taking a template of the bay and the track will come shaped and ready to fit. The cheaper option is to use a plastic track and bend it by hand to the shape of the bay. With ring top and tab top curtains the will only fit on a pole so the custom pole option is the only available.
Ready made curtains although fine to fit in bays do only come in limited widths the largest being 90″. So often the curtains will need to be made to measure curtains.