If you want to design some custom cornice boards this page has some practical design tips I hope you find useful. There are also some ideas to show the variety of shapes you can use.
We'll go into more details of how to make your cornice boards in the Making section, so lets press on and consider some factors which will affect the decisions you make.
Large windows give you the scope to have longer 'ears' for your design. These are the side sections which are traditionally longer than the center section. The center part can then be kept straight, or you can have gentle curves to provide a change from straight lines.
A large cornice can incorporate more changes in shape than a small one, so you have more scope for creative designs.
I've heard it said that you shouldn't use custom cornice boards on small windows. Why not? As long as they are in proportion, go ahead. I've been making them for windows as small as 3'0" (about 1m) wide for years.
A general rule if you're making a shaped cornice for a small window - especially if the drapes are sill length - is to keep the sides shallow, just a little bit deeper than the center section.
In the top sketch on the right, the distance (A) on a large cornice is about half the total depth. The lower sketch shows a smaller cornice, and here the depth of the sides has been kept shallow.
Keep the shape for a small cornice very simple. Don't have lots of sudden changes in the shape.
Small cornices benefit from regular, repeating shapes, such as a scalloped base.
Here are some ideas to get you started. Don't forget that these are just the basic shapes. You can add all sorts of accessories to them, such as rope, braid, fringes, padded borders, etc.
There's more information about cornice designs here. This section includes guidance on using patterned fabrics.
Sometimes you won't have much space above your window. If you have a crown molding as well, this can prevent you from fitting the mounting board as high as you'd like.
So fit the board up against the molding. When you come to make the returns for the cornice, cut out a pattern for the molding shape, transfer it to the returns and cut out the shape. Then you can fit the cornice up against the ceiling, making the most of the space above the window.
Make sure your custom cornice boards balance with the room decor. If your room is minimalist, you won't want sweeping curves and elaborate fringes. In fact, if the style is minimalist you may not want to use drapery in the first place!
A Victorian style would almost demand a heavy pole, an elaborate cornice, or lots of swags. Art Nouveau would require something simple for your cornice. This is where you might like to do some research.
When cutting out your cornice design, cut out one side first, then use that as a template for the other side.
For buckram, fold the buckram over and mark out the outline.
For wood, keep the off cuts from one side, place them in position on the other side and mark the shape.
Check your design by making a full sized section of it (a couple of feet of one end would be enough) and hold it up to the window. It will give you a good idea of how the finished result will look.
Don't try anything too elaborate, especially if this is your first time designing custom cornice boards..
Do make sure the mounting board is very firmly fixed to the wall.
When you pin the fabric on the front of an upholstered wood cornice, make sure that the seams are perfectly vertical. It's very easy for the seams to start to pull left or right, especially when there is tension in the fabric. Vertical seams are hardly noticeable, but ones which start to deviate stand out like you wouldn't believe!