The curtains are sold in pairs. The sizes stated refer to each single curtain. For the total width, double the width of a single curtain.
Since the fabric will shrink when washing it is a good idea to wash the curtains prior to cutting/hemming.
Use SY iron-on hemming strip to shorten the curtains without sewing.
16 gliders and hooks are usually recommended for each curtain with a width of 57⅛". You can increase or decrease the number depending on whether you want narrower or fuller folds in the pleats.
