The waist facing for my bib-front sailor trousers required finishing the raw edge of an inside corner. The pattern didn’t describe how to do this and my internet searches were in vain. I’d never come cross a bias bound inside corner before but having mitered the hem of a lined vent how hard could it be to work out? This is more of a here’s what I did rather than a tutorial because, although it works, there’s surely more than one way of doing this.
I started with the obvious: an inside corner raw edge and some bias binding.
On the wrong side of the facing at the inside corners I marked my seamline for the bias binding and another parallel line. Then I joined these two corners to the raw edge corner (three points make a more accurate straight line).
Next I cut into the first intersection, just before the seam line. If I hadn’t used fusible interfacing I would have reinforced this by sewing along the seam line before cutting.
Stopping at the marked intersection, I lowered the needle and raised the presser foot.
Keeping the bias binding in the same position, I pulled the facing (this is where the cut into the corner helps) towards me and lined it up with the bias binding.
Once I’d aligned the raw edges of the facing and the bias binding, I pinned the next straight edge and continued to sew.
Repeating the process at the second inside corner I was left with something looking like this.
I pushed the short seam allowance of the bias binding through the cut in the facing and snipped into it too.
After a good press of the bias away from the right side of the facing (ignoring the corners for the time being) I pushed the wider remaining part of the bias binding through the same snipped corner.
Time for folding. I made and pressed the first fold of the bias binding towards the raw edges on all sides (again, ignoring the corners).
Concentrating one straight edge only, I made the second fold to just cover the first line of stitches.
At the corner, I pulled the bias binding so that the second fold I had been making continued past the first seam line corner.
After pinning the straight edge, I flipped the facing to have the right side up. First lifting the next straight edge of bias binding upwards and smoothing the folded part as far into the corner as possible.
Second, I folded it down like an envelope flap.
And finally I flipped back to the wrong side, made the second fold along that straight edge and repeated at the next corner. Stitching in the ditch on the right side secured the bias binding in place.