The next part of the sock is known as the gusset.
To shape the gusset, you have to rejoin the stitches you left behind to shape the heel.
Double elasticated leg gusset holds pad folded diapers well.
Gusset Envelope Has a gusset Envelope Has a gusset along each side of the envelope to allow for bulky mailings.
The front panel features a gusset on each side.