Things You'll Need
A swag valance can be a simple way to dress up a window and can be used to either complement an existing set of curtain panels or can stand alone to give a window an open but finished look. Swag valances are some of the easiest window treatments to make yourself, since they only require a straight line to sew and mostly require draping instead of tabs or pockets. Even beginners won't be intimidated by this simple project.
Determine how deep you want your valance to be over the window and how far down each side you would like it to hang (only in the event of a valance that is not going over the top of an existing set of panels).
Measure the length of your curtain rod and the length down one side as far as you want the end of the swag valance to hang. Double this measurement for the length when you choose your material.
Determine the width of your material by measuring from the top of the curtain rod to the lowest point on the window where you want the swag valance to hang. Add 6 inches to this measurement for hemming and draping allowance.
Choose a material that drapes easily and fluidly, such as silk, faux silk or soft velvet. It is also helpful if you choose a material that doesn't fray easily to make hemming easier and smoother. When choosing your fabric at the store, check the raw edge to see if it unravels easily.
Cut the material to your predetermined measurements. Before hemming, give the valance a test run by draping it over the curtain rod to test the width and length. You should have plenty of extra material to work with, so adjust as necessary.
Fold the edges of the material in 1/4 inch and iron them to help them lay flat. Sew a straight seam 1/8 inch from the edge all the way around. Fold the edges in one more 1/2 inch and iron again. Sew a straight seam 1/4 inch from the edge of the fabric all the way around the perimeter of the piece. Snip off any hanging threads.
Drape the valance over the top of the curtain rod with the center of the valance hanging over the front of the rod and and the end sections behind to keep it in place. Adjust the front of the valance to the predetermined vertical length. If the swag valance is being used over the top of curtain panels, make sure the end pieces are tucked behind and out of sight. If the swag valance is on its own, drape the sides decoratively.
Always add more material to your measurements if you aren't entirely sure about the length and width. The cost for the extra material will ultimately matter less than the frustration of coming up shorter than you expected and you may find you like it better longer than you thought you would when you envisioned it. You can always cut it back but you can't make it longer.
If you are using your valance as a sole window treatment, get creative with the draping style by wrapping it in loops over the curtain rod or using uneven lengths on the end pieces.