Hi Lasaka!
Thanks for the interest! I hope this does not offend anyone, but I can't think of a better way to explain it.
The waist band is a 4" wide black elastic ( Black is more hygenic!). It should be tight enough to stay up comfortably at the waist, and exert some upward tendency to keep the rest tight.
The 4 shots show the front, when its is folded (Tucked ), a side view, and the back with a press stud ... I put in 2 receivers, but I only use the tightest one.
Thin black leather is the go and it is easy to sew. It also forms to the body with use ... so its self adjusting to a degree.
It is a good idea to make the pouch loose so that putting it on is easy, but tight enough that the boys can't get in, and stay up in their spot. The pouch has a part at the end which is not sewn together so that you can poke thru when you need to pee. A bit of baby powder helps putting it on. Going to the toilet is easy ... Unclip the press stud, extend a bit .. do your thing, dry off, and clip it back ... No problem ...
Good luck!
