Bra seams - why you need to know what direction to put them in

If you're designing bras or even just trying bras on, chances are, you've never thought or paid heed to which direction a bra seam is going and why.

A seam on a bra alone, can alter the fit, and by understanding what way they go and why, could make your designing easier, and give you the knowledge during fits to know what to alter.

In layman terms, the seam of a bra will tell you the direction in which it will lift the breast.

Looking at underwire bras, you usually have the following styles, darted, horizontal, vertical, 3-piece cup and four piece cup.

DARTED CUP

They’re more for shaping than for any kind of support. They work well in smaller cup sizes, or crop tops that need more support than just a flat piece of fabric. With a darted bra, the bra cup is made from a single piece of fabric and this seam allows the bottom of the cup to be deeper.

HORIZONTAL SEAM

This seam design tends to be for the smaller cups again, they give the bra a good depth but tend to lead the breast outwards. The cup is made of two pieces of fabrics a top cup and a bottom cup.

VERTICAL SEAMS

A vertically-seamed bra goes from the base of the cup to the top - there may be just one central seam or two or three seams. The cups are made from two (side cup and front cup) or more pieces of fabric. A  vertical center seam is very supportive and gives an uplifting effect to the breasts, as the seam is directing your breasts upwards.

A vertical seam bra from Vanjo

THREE PIECE CUP

As the name suggests, this cup style is made from 3 pieces of fabric – two at the bottom and one at the top. The bottom section has a vertical seam which provides support and uplift.

There are two different types of three-piece-cup bras, both have a vertical seam on the bottom cup which will help lift the breast upwards but one has a horizontal seam across the breast which will give the breast an outward lift.  This three-part cup offers a lot of support but slightly less uplift than a purely vertically-seamed one.

The other three-piece style has a diagonal seam which leads up into the strap, this draws the breast tissue inwards from the body and up. So your breasts will looks more centred.

FOUR PIECE CUP

This cup has a bottom cup with a vertical seam and top cup, like the three-piece-cup but it also has a side panel leading into the strap that runs the full height of the cup. This is popular in the bigger cup sizes as the breast tissue can be contained within the cup by multi different ways of the seams.

For more information about cup shapes see below: