How a bra band is put together
Short answer: The band under the cups consists of an elastic, a piece of fabric and an edge finish, sewn together in several rows. It is the part that carries most of the weight, which is why it is the most reinforced place in a bra.
The band does the work
Most of the support comes from the horizontal band, not from the straps. It lies around the ribcage and keeps the bra in place so the cups can do their part. That is why the band is always the most reinforced place in a bra, and where the construction is most careful. See bamboo bra without underwire.
Layer on layer
A strong elastic is laid between layers of fabric, and the edge is closed with a narrow seam or a binding. Several rows of stitches spread the pull over a wider area, so no single seam has to carry it all. The fabric against the skin is soft, while the elastic in the middle provides the force.
The elastic in the middle
The elastic is what gives the band its tension. It stretches when you put the bra on and contracts so the band sits close around the body. The quality of the elastic decides how long the band keeps its strength. The fabric layers around it protect it from wear and stop it rubbing the skin.
Why the band fails first
The elastic in the band stretches with every breath and every movement. When it tires, the support goes, even though the fabric is still whole. That is why a bra often feels slack long before it looks worn. See women's bamboo pants and bamboo panties for other clothes with elastic under similar strain.
When the elastic is tired
You notice it when the band creeps up your back or you need a looser hook than before. The fabric still looks fine, but the band no longer tightens. That is not a fault in the sewing but a sign the elastic has done its job. It happens slowly, and most people notice it only after long use.
Why the band creeps up the back
Because the elastic has become too loose, or the size is too big. A band without enough tension cannot hold against the weight of the cups and so slides upwards. First check that you have the right size. If it is right, it can be a sign the elastic is tired.
Can the band be tightened
Only with a hook further in, and only until the elastic is completely tired. A hook further in gives a tighter band but does not solve the elastic having lost its spring. At some point the band has nothing more to give, and tightening further does not help. Then it is time for a new one.
Caring for the band
Wash the bra as instructed, use a gentle programme and avoid wringing it. Heat and rough treatment wear on the elastic, so let it dry without pulling at the band. A wash bag can help keep hooks and band in shape. With a little care the elastic keeps its spring for longer.
Frequently asked questions
How much of the support comes from the band
Most of it. The straps carry only a smaller part of the weight, which is why the band is the most reinforced place and the first to lose strength when the elastic tires.
Why does the band creep up the back
Because the elastic has become too loose, or the size is too big. Check the size first, then see whether the elastic still tightens as it should.
Can the band be tightened
Only with a hook further in, and only until the elastic is completely tired. After that the band has nothing more to give, and it is time for a new bra.
You can find the full range at Bamboo-Clothing.com.
