So, tartlet, sorry for not getting a chance to put up a review yesterday of the belly band!
https://www.target.com/p/be-maternity-beband-assorted-colors/-/A-11084904
Bought this last week. I've always needed a belt to stop my pants from sticking out in the back, so even if the hair tie trick works with my pants (and it doesn't for most of them anymore), it doesn't help that problem.
So, first of all, the woman in the product pic definitely has the band folded over. That's how I've been wearing it. It's looser up top to allow for growth, so it'll be more comfortable unfolded later. For now having it folded provides extra support on my pants and is more comfortable.
It stays put pretty well. If I'm bending down a lot it moves some, but is easy enough to put back in place. I'm not sure if it's how I sit or wiggle around when I'm driving (and I do, dislocated my tailbone years ago and haven't been able to sit flat for more than a few minutes since then), but it does bunch up in the car. It's no worse than how many of my tighter shirts bunch up in the back, so it doesn't bother me.
It definitely works to help hide that my pants are unbuttoned, and feels much more secure than the hair tie alone (a couple of times I used the hair tie plus the band together). Can't wait to be able to try it unfolded when I'm bigger! It does feel like it will stretch without a problem (and I'm using the size S/M, there's a sizing chart on the package that goes based on three things - if your hips are bigger than your waist or vice versa, your pre-pregnancy size and if you're having multiples)
One note - be careful of your pants zipper. If it's sticking out, it pokes right through the fabric and I'm afraid of it tearing.
Pics of folded and unfolded -
https://i.imgur.com/nDSzC.jpg
https://i.imgur.com/7Zrrk.jpg
Sizing Chart:
Smaller Hips, pre-preg size 0-11 - S/M
Smaller Hips, pre-preg size 11-18+ - M/L
Smaller Waist, pre-preg size 0-9 - S/M
Smaller Waist, pre-preg size 9-18+ - M/L
Pregnant with Multiples, pre-preg size 0-5 - S/M
Pregnant with Multiples, pre-preg size 5-18+ - M/L