Now you may be wondering what is the big deal?
So far i have heard that sweetheart or any other sharp curve included shapes need self-shaped facing and wouldn't turn up nice when done using bias strips.
But i wanted to try if it would work by pinching the bias strip a bit at every sharp turn in the neckline. It turned out pretty well. Will get action shot when my MIL will wear it.
Bias strips were prepared for neckline usage, by ironing them under steam and stretching them just a little bit while doing so, Believe me the bias strips will shrink a bit and will be ready for usage for any shape of hem or neckline facing.
Try it out. Shall later update the post with pics of bias strips before ironing and after ironing.
Neckline on the outside, will get a better idea of the shape when worn, will post pic soon.
Notice the pinched bias strips....