Nearly two years ago, I took an old idea I'd used on a much earlier thrifted skirt and applied it to a freshly-made skirt. It turned out well, but...the waistband was, even then, too small to be comfortable.
Since that skirt was made from the sheath version of New Look 6843, it would have been cut in size 16. So my brain, after making the size 16 New Look 6843 sheath skirt in the previous post work, wondered if I could do something similar with this one.
The first thing I did was remove the waistband. I let out the back darts by stitching from the point to the edge, tapering to a presser-foot-width from the upper edges, on both the shell and lining darts. Then I picked out the original stitches. I couldn't let out the front darts, because one had been decoratively stitched over so it would have been some trouble to change, and I wanted to keep the front symmetrical so I didn't touch the other dart. Instead, I let out the upper side seams by sewing from the original stitching a few inches above the hem, tapering quickly to a presser-foot-width inside the edge of the serged seam finishing. Then I removed the original stitching in those areas and pressed everything.
I barely had enough of the wool blend fabric to make the original waist band (I had forgotten that it was pieced) so it was no problem deciding to use a different fabric for the replacement, larger waistband. I used the same black twill as another (A-line) 6843, but made it as wide as the waistband from Simplicity 9815. The shades of black of the twill and the wool blend aren't the same, but I don't generally dress in a way that exposes waistbands, so it gets a pass.
(If I ever get a proper belt, I might add belt loops.)
