In estimating the yardage required, consider the length of the drapery, before finishing hems and heading, and the width of the window or space to be covered. An allowance of 2½ or 3 times the width should be made for fullness. When using sheer fabrics, draperies should be full enough to hang in easy, graceful folds. Over-curtains or draperies of medium weight fabrics require a fullness of 2 to 2½ times the width. Also, if you select a fabric with a large one-way design, some allowance should be made for matching the design so all lengths will balance.
For example: The window is 64″ wide which requires 4 widths of 48″ wide fabric for a 3 to 1 fullness. The drapery lengths are 2⅓ yards long. If a plain fabric or overall design is used, the fabric required would be 9⅓ yards, but if the fabric has a 24″ repeat pattern, you must allow 1⅓ yards more, or a total of 10⅔ yards for matching the design.
Consider the width of the fabric when figuring the number of widths for fullness. Some fabrics are only 36″ wide—chintz and some polished cottons, for example. Others may run 40″—48″—even 54″ or 60″ in width; but the average is about 48″ wide.
Grain lines of fabric.
⇐Crosswise Grain—Weft or Filling⇒ ⇐Lengthwise Grain—Warp⇒ ⇐True Bias⇒
Draperies must be cut on the true lengthwise and crosswise grain of the fabric so that when hung, they fall straight from the rod in even, graceful folds.
In weaving, yarns are threaded lengthwise on a loom which form the warp of the fabric. Another yarn is interlaced back and forth crosswise and is called the weft or filling thread. This is known as the plain weave. Linen, voile, chintz, etc., are a few of the plain woven fabrics. There are variations of the plain weave, such as the pile weave, with velveteen and corduroy as examples. The basket weave is another, with Monk’s cloth as an example. The diagonal line halfway between the lengthwise and crosswise threads is the bias of the fabric.
The twill weave is perhaps one of the most durable. The filling yarn forms a diagonal line, passing over one warp yarn and under two or more. Denim, drill cloth and ticking are examples of this weave.
The satin weave is an irregular weave where one yarn passes over several yarns of the other set before interweaving, forming a floating, lustrous surface.