There is quite the proceedure for finding the center of the pants and drawing lines. This is needed to line the two halves up. Well I spent painful hours trying to get it right. Nothing is perfectly square. I hope I got it OK on the tops ends and points of maximum pressure at the front. The 2 ply pant parts are pretty 'floppy'
If I have it wrong the pants will produce more drag than they could have.
Getting everything perfectly straight is not my strong point. I used Wayne Hick's instructions and he still may have done a better job that I have. That said, I do have lines on the 4 pant halves.