Sewing fabrics together with machined seams
For the best results when sewing fabrics together use a machine. Although there are many ways of seaming panels together, we shall concentrate on just two of them. Once you've mastered these, you'll be able to make any drapes you like.
This seam is used for joining widths of fabric together, and for joining lining.
Plain seam for joining widths of fabric
Make sure your sewing machine is set up correctly, and you are using the right needles and thread for the job. Nearly all problems with seams are to do with thread tensions incorrectly set, or the wrong needles are being used.
Take two cuts of your fabric and place them with the front sides together. Then machine a line of stitching. Make sure the seam allowance includes the selvage, otherwise you'll have an unsightly edge showing on either side of the join on the front.
Back of lining showing plain seam. (The photo has been adjusted for lighting and contrast to show up the details.)
If you're joining patterned fabric, it might be advisable to slip tack along the front of the join first so you get a good match. Or pin the two sides together with pins at right angles to the seam.
When using a fabric which has a tight weave you could use a seam allowance of about 0.5" (1.5cms). If the cloth is more loosely woven then increase the seam allowance.
Once the seam is completed, put the fabric face down on your table and iron the seams flat.
Single lapped seam
Single lapped seam for joining interlining
Use this seam when joining interlining, especially if it's a very thick variety. You'll get a much flatter seam which prevents bulging in the drapes.
All you have to do is overlap the selvages by about 0.3" (1.0cm) and machine a line of stitching.
Remember, keep all your seams very neat!
There are occasions when strong light coming through your drapes may show up the outlines of the seams. Keep all your work neat and tidy.
Here's some useful information on sewing straight seams from About.com, part of the New York Times Company. The link opens in a new window.
About joining widths
Always have half widths on the outside
When you have an uneven number of widths for a pair of drapes, always place the half widths on the outsides.
Very occasionally if you're making drapes for two identical windows you may find that you can use quarter widths. In a similar way, always have the quarter widths on the outsides.
When it comes to making up a valance, you should always have a single width in the center. So if you're using an uneven number of widths, just join them up.
Arranging half widths for cornice boxes and valances
But if you have an even number, work outwards from the center. This means you'll have a half width on the outsides, as shown in the illustration. If you don't, you'll have a seam in the center and that looks very unprofessional!
The same applies to cornice boxes. Always have a complete width of fabric in the center and work your way out to the sides. (This is similar to using wallpaper on a chimney breast, for example. You place the first width of paper in the center and then work outwards.)
These are the only two machine seams you need to master in order to make all sorts of drapes. If you've never used a machine to seam up fabric, don't worry, it's really easy to do.
Practice using some old fabrics or linings and you'll soon be sewing fabrics with beautiful straight seams.