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bra construction

We’ve all got a bra that we love simply because of the shape it gives us. So you’ll know already that your breasts can look quite different depending on which bra you’ve got on. Some will give you lots of lift, some won’t, some create a very rounded profile, some one that’s a bit pointier or flatter… But why is this? And how can you predict what shape a bra is going to create when you’re shopping online and can’t try it on?

Below I run through some of the construction basics of a bra that affect its shape: 

What do bra seams do?

What’s the point of seams in a bra? Rather a lot as it happens – they’re fundamental to creating the bra’s unique shape.

Vertical seams

Vertical seams are there for support. The seam is thicker than the fabric surrounding it, and therefore stronger. Imagine holding something heavy inside a piece of thin fabric. The lowest point where the strain on the fabric is at its highest is going to stretch and deform.

Your breast is like that object, and adding a strip of reinforced fabric prevents the cup from warping so that the bra holds its shape better. Typically, if there’s a vertical seam it’ll be up the centre of the cup where it’s under the most strain. Some bras though have multiple vertical seams, for lots of upwards lift!

Horizontal seams

Horizontal seams on the other hand don’t affect the amount of lift the bra has. Instead, they’re there to give it more ‘forwards projection’. A totally horizontal seam that runs straight across the nipple will create a more perky, pointed shape. One that runs slightly diagonally, up towards the strap, will create more of a rounded shape.

Seam combinations

A popular bra style is the ‘3 part cup’ – the bottom part has a vertical seam, but it’s cut off by a horizontal/diagonal one instead of reaching all the way to the top of the cup.

A bra that is only vertically-seamed is very uplifting, but can make your chest look somewhat flat from the side. So this combination of vertical support and horizontal shaping creates a shape that is both lifted and rounded. Full-busted women in particular tend to love it!

Related: 3 Important Factors That Determine Your Bra Band Size

What else affects bra shape?

Seams are very important, but they’re not the only thing that influences bra shaping. With bras being such intricate garments – often containing dozens of individual pieces and components – there are all sorts of ways for designers to tweak the basic shape of a bra.

Side supports

A side support is a vertical piece of fabric reaching from the base of the bra up to the strap. It may be a part of the cup itself, or a separate sling inside the bra. The point of a side support is to stop breasts splaying out sideways. The support pushes breast tissue at the outer edges inwards, creating a narrower shape from the front and a more projected one when seen from the side.

Gore size

The gore is the little piece of fabric at the centre-front, between the two cups. Some bras have a wide gore, with maybe as much as an inch between the two underwires. On other bras, it’s much more narrow – the wires may even be touching.

A wider gore will help to separate your breasts, and a narrow one will therefore hold them closer together. If you’re aiming for cleavage, you want as narrow a gore as possible.

Underwire shape

The underwire sits right at the base of your breast, and is designed to mold the soft breast tissue above into a particular shape. The narrower the U shape of the wire, the narrower (and therefore more projected) a shape you’ll have in it. Though be sure it is still sitting entirely under your breast – if it’s on top of it, it’s too small and you need a larger cup size.

There are also plunge bra underwires, which are less U-shaped and more like a J, not coming up very high on the inner side. This allows your breast to ‘spill over’ as it were at the centre, creating cleavage.

Molding and padding

Some people love unlined bras, others swear by molded ones. In a molded bra, the cup is pre-formed using heat, and retains its shape when you take it off. It’s therefore perfect for giving you a very smooth, round shape. Many molded cups don’t even require seaming because they hold their shape so well, though you can find molded bras with seams for adding support.

Padding is an extra-thick area inside the bra cup designed to give you the appearance of a larger bust. The padding may be built-in, or in the form of removable pads. If the padding is across the bottom of the cup, your breasts rest on top of it and therefore sit higher on your chest. If the padding is towards the outer side of the cup, it forces your breast tissue inwards – another way to create cleavage.

Now go find a bra you love!

You can refer back to this guide when shopping online, to get a sense of how the bra is going to look and fit. Take a moment to analyse that favourite bra of yours, the one that you love the shape of. Which direction do the seams go in? How wide is the gore? Are there side supports? Note down the key construction features, and you’ll be better able to hunt down bras by other brands that will fit in a similar way.

Related: The Complete Guide To Breast Shapes

We Highly Recommend

Whether you’re shopping for new everyday bras or lingerie for a special occasion, it’s always a good idea to seek out a second opinion. We know how hard it is to find bras that fit well and feel good, especially when you’re doing it on your own. If you’ve ever felt unsure about your bra size or you just don’t know where to go to find good bras, it’s time to let a bra fitter help.

Many specialty lingerie boutiques offer bra fittings. Their expert bra fitters will take the pain and frustration out of bra shopping and do all the work for you. Even better, their product knowledge can save you time and money. Plus, they know where all of the best bras are hiding.

If you’ve struggled with finding bras in the right size, it’s time to make a change. Visit our specialty store locator to find a store near you and schedule an appointment.

Happy bra shopping!

Featured image lingerie:
Parfait Matilda Contour Plunge Padded Bra P5311 in Bisque

What’s your favourite type of bra construction?

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Published by

Estelle Puleston

Estelle Puleston is the founder of, a blog dedicated to her love of lingerie. She works full-time as a copywriter and digital marketer for the lingerie and swimwear industry, and when she’s not doing that, she’s probably sewing or enjoying a good cup of tea.

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