There are quite a few reasons why a V neckline gapes.
V necks can gape, because when the fabric is cut it usually ends up on the bias. The sewing of anything on the bias is tricky, due to fabric stretching with the action of the feed dog of the machine, the needle and the thread all stressing the fabric and the result is a neckline way bigger than the pattern piece.
On the pattern making front, maybe the neckline is too wide or the neckline is too deep for your bust shape. Taking the neckline in slightly on the shoulder seam, even a centimeter, can dramatically change how a neck opening will behave.
Also, our busts are all different, and sometimes there is an indentation on our chests, and the material has nowhere to go. So, basically there is a little dart in there that needs to be attended to, somehow.
QUICK WAYS TO FIX IT
Knit fabrics do stretch and gape, but are often fixed easily by sewing on the neck binding/finish a bit tighter than the neck measurement, but sewing dresses and tops from woven fabrics is another thing entirely.
Sew 2 or 3 lines of basting (big stitches) around the neck, and pull up the neckline ever so carefully to remove the extra fabric. 3 lines of basting is nice because you really can smooth out fabric well. Try on the garment and check to see how it looks. Sometimes I even pull it up a bit more so that any chance of further stretching of the fabric while sewing is taken into account. Sew on facing/binding/lining, whichever is called for.
Does your machine have a presser foot button to release pressure on the material? Loosen it up so the fabric doesn't get SQUEEEEEZED and stretched when you sew tricky bits.
Maybe the shoulders could be taken up a bit to get rid of the problem? This is a quick fix option which could work.
|neckline is gaping on one side|
Here's a garment that has already been made, and unfortunately it's not right on one side. Have a look at this blog here, its a good way to fix a garment like this.
removing extra fabric on a paneled top
WAYS TO PREVENT THE PROBLEM IN THE FIRST PLACE
Sew a sample muslin to check the neckline out. and Pin and take out the excess on your pattern, here I found an excellent tutorial on how to do this... fixing the pattern after doing a muslin
You could even get away with holding the pattern up on your body and getting someone to pin out the excess.(I am always finding ways to avoid any extra sewing at all!)
Cut a thin sliver (just over the width of your seam allowance) of fusible interfacing and stick it onto the material, on the wrong side of the fabric, obviously! This will hold the shape of the fabric better. You can sew over this and it holds the fabric .
And, of course, this method could be used on other necklines that have a tendency to gape. Take a look at how you can avoid gaping strapless tops on wedding dresses from a very knowledgeable MrsC. In this case she puts the tape on the lining of the garment, as the fabric is organza.
My sincere thanks to the ladies who have blogged on this subject, without you I would be spending far too much of my time blogging away....
Love em! Hate 'em!
Learn how to deal with them and sewing them is much more pleasant.