It's a question that's never really been asked on here before, you take stuff on this board way too seriously man, no one is attacking you.
Didn't think anyone was...just find it strange that someone cares where the pro's get their trunks.
For what it's worth, here's your answer:
Most of them dont do anything but contact CJ, who's been in the business for many years, and caters to the men and women of the IFBB to provide trunks/ bikini's custom made (and usually free of charge)...
She's probabaly THEE most important person backstage, as I've seen her come to the rescue many a time to the women (for the most part) who have wardrobe malfunctions...
So here's the recap for you;
Call is made to CJ
She ask's your height and weight
You explain how you like them to fit
She ask's if there is any color you like in particular
She fed-ex's them to you
Pterry exciting, huh?