Your breasts have a natural "crease line" where the underwire should fit comfortably against your ribcage.
The diameter of your underwire is too small if the underarm end is poking breast tissue, or catches your arm
as it moves forward. The diameter of your underwire is too large if the underarm end is poking into your armpit.
The best underwire for you is one that encircles your breast, giving you a more rounded and defined look.
Women short in stature usually find that underwires poke them under their arms. An instant solution is to select
demi cup bras - the wires are shorter and thus will not poke.
Elements of the Perfect Fit - Center Panel
It's best if the center panel between the cups of your bra sits firmly
against your chest (sternum). However, there are some exceptions.
Women with full breasts close together may not be able to achieve
a center panel touching their sternum. The center panel of Wire-free
(soft cup) bras may also not sit quite as firmly against your chest.
Elements of the Perfect Fit - Straps
Shoulder straps on a bra should rest flat on your shoulders. They shouldn't cause dents or fall off your shoulders.
Shoulder straps are designed to carry minimal breast weight (10% or less). If your shoulders have dents from your straps, then your
straps are working too hard - you probably need a smaller band size to give your bra more support.
• If your straps keep slipping, there are several possible causes:
the placement of the straps on your bra may be too wide. Wide-set straps are a popular look right now and are common on push-up
bras due to the fact that wide-set straps tend to put breast tissue inward to maximize cleavage.
If you're wearing push up bras and are having this problem, you need to find another style.
• If your cup size is too large, there will not be enough breast tissue to fill out the top of your cup and this will cause your straps
to slide down your shoulders.
• The straps could also be sewn too far apart on the back of your bra.
• If the strap in front and/or back is attached to a ring this ring
allows the strap to swivel and could cause the strap to fall off