This is the footed, turtleneck unitard I got from  It is cut and seamed same as the one from the film. Taped around the perimeter.  I will mark and cut about 1"-2" wider so that the unitard will stretch flat onto it. Hard to see, but I used a Sharpie to draw some cut lines on the left half. Using a straight edge and utility knife to cut the corrugated vinyl.  I placed a cut board underneath. Left half is cut. On the back, I cut through the surface of a corrugated rib so it will fold easily. Now I can trace the right half.  Guess I didn't need to tape it up. Symmetrically cut unitard stretching board. I trimmed the waste in some more, then fitted the unitard onto it.