Small holes, tears. Darn or patch. See
clothing—fabrics.
Large tears. Anything you do for a large horizontal tear will be makeshift. If fabric is heavy, the least obvious repair will be made by bringing torn edges together carefully and covering with press-on mending tape. If fabric is sheer, machine stitching is best.
For large vertical tears, rip the material all the way to the bottom, turn edges under and sew on a machine. An even better job is done by putting a seam in all the way from the bottom to the top of the drapery.
See also
clothing—fabrics;
clothing—hems;
clothing—seams.