When sewing lengths of neckties together for a skirt or other project, it helps to stabilize the seam lines before sewing.  A 1/2" wide strip of sheer-weight fusible knit interfacing centered on wrong side at all seam lines gives enough body that the seams will not stretch when sewn, but will still drape nicely.  Londa Rohlfing (www.londas-sewing.com) recommends and sells a ready-made tape that accomplishes the same purpose.