To construct the internal belt of the jumpsuit, begin by opening it and laying it flat on the floor or your workspace. Open the fronts as much as possible so you have a clear view of the back elastic channels and spandex panel.
Measure a length of 2" grossgrain ribbon or belting that extends from the back of one elastic channel to the other, plus about 2".
Cut the length of ribbon or belting.
Turn the ends under about 1" and sew them down.
Press the ribbon briefly to flatten the ends.
Sew this length of ribbon or belting to the back ends of the waistband elastic that you left poking out of the back ends of the channels earlier.
Cut two more lengths of ribbon or belting at least 12" to 16" long.
Turn one end of each under about 1," then sew and press them each in the same manner as done previously with the back of the internal belt.
Sew the sewn/pressed ends to the front ends of the waistband elastic that you left poking out of the front ends of the channels, just as you did for the back.
Leave the two front lengths of ribbon or belting dangling for now.
And now, the time has come for you to put on your jumpsuit!
Pull the two lengths of ribbon or belting together, as symmetrically as possible, to a comfortable tautness.
Pin (or even double-pin) the two lengths of ribbon or belting together at the front center.
TIP: We recommend wearing your undershirt shirt plus any other undergarments you plan on wearing, as these may affect the necessary tautness of the belt, either by adding a modest but significant amount of bulk and/or by compressing your torso a bit (such as if you're wearing, say, Under Armour or your undershirt is on the small side).
Cut both ribbons approximately 1" from your pins' placement.
Turn these ends under ¾" (not 1", since they will overlap slightly), then sew and press them as done previously.
Hand sew two trouser-style hook-and-eye closures to the ribbon/belting.
Your jumpsuit's finished internal belt should now look something like this: