- Unless you are using extremely stiff fabric or you want a flat valance, multiply the width of the window by 1.5 to 2 for the desired width.
For example: For a 36" wide window -- using a fairly stiff fabric -- 36 X 1.5 = 54" If your fabric is 45" wide you will need to seam the fabric for the desired width.
Although a 30 - 32 inch wide window would calculate out at (30" X 1.5 = 45) or (32 X 1.5 = 48") it is your call as to if you will be adding extra width to 45" wide fabric.
If you only need a few extra inches and want the extra width, sew together two equal pieces to make the width instead of just adding a couple inches on one side. OR Sew two separate valances and use the two valances.
- Always pre-shrink the fabric and trim away the selvedge.
- Once of the beauties of sewing your own window treatments is that you decide the length of the finished product.
- Measure from the top of the curtain rod to the desired finished length. (Example 12")
- Add 3" for a header above the curtain rod. (Example 12" + 3")
- Add 5" for the hem behind the header and the curtain rod pocket. (Example 12" + 3" + 5")
- Now add for a hem seam allowance. The hem will be a separate facing. (Example 12" + 3" + 5" + 1/2" = 20 1/2"= length)
Body of the valance will be the width by the length.
- You will need a facing to hem a scalloped valance.
- The width of the hem facing is the same as the width of the valance.
- The length of the hem facing will vary by how deep your scallops are. You will need a hem facing that is at least 1.5" longer than the depth of your scallops. (See step 4 for complete hem facing information.)