Article in English: In order to pinpoint where a bra does or does not fit well, be aware of the various part of a bra.  The cup: The part where your breasts fit into. It’s usually made of stretchy fabric, and can have up to 3 tailored seams. The band: This is the elastic part that goes all the way around your chest. The wings: These are the portions of the band that extend from the end of the cups to the center of the back. The straps: These go over the shoulders and are often adjustable, and sometimes padded. The closure: This is usually a hook and eye set at the center back. However, it can also be in front, or absent. The center gore: This is the part between the cups in the front. If you appear to have 4, you have what is called the “quad boob effect.” This indicates that the cups are too small, and there's not enough room inside. This is especially apparent if you try your shirt on over your bra. If it does, this means that the band is too loose.  Try raising your arms and bending backward a bit to check if this happens. Remember, when you go up a band size, go down a cup size. If it won’t, then the bra doesn't fit.  This could be because the underwire is the wrong shape for your breasts. It could also indicate that the cup size is either too large or too small. You should be able to run your fingers around under the edge of the fabric.  If you can pull it away from your back by more than 1–2 inches (2.5–5.1 cm), it's too loose. If the band digs into your sides to the extent that it causes pain after wearing it, the band is too small. If the band rides up, try loosening the straps. If this doesn’t work, the band is too big. This does not necessarily mean the band is too tight.  Instead, look for bras that have a wider band or a “leotard band” to create a smoother silhouette. Unless the band is causing you pain, don’t go up a band size, otherwise you will not have enough support. This could also indicate that the cup size is too small.  Another solution is to wear a body shaping undergarment. This could mean that the cup...

Summary in Chinese:
了解文胸的构成。 观察胸的形状。 检查一下文胸不会滑到胸上面去。 检查一下文胸的中心部位是不是平的。 检查一下胸围会跑上去还是会嵌进你的肉里。 后背赘肉是非常正常的。 要确定罩杯不皱或上端没有空隙。 检查一下肩带有没有嵌进肩膀中。 检查一下肩带是不是会滑落。 要确定钢圈是否舒服。