What Makes a Supportive Full Bust Bra Work?
by @sheandreverie
When a bra is sized up, it takes more engineering than, say, a t-shirt. For a t-shirt, you really only need to make it wider around, maybe a little bit longer. For a bra, there are so many aspects that need to be adjusted, and sheer size is just one of them.
Almost every aspect of a bra needs to be readjusted for larger cup sizes, starting with thicker straps. Pretty, thin elastic straps are probably not going to cut it. Although most of the support of a bra should come from the band, the straps often need to be made of a thicker, sturdier elastic for D+ cup styles. It’s more expensive to source multiple widths of the same elastic, and it can change the look of the bra, so manufacturers who are sizing up often skip this detail during development. However, stretched-out, rolling elastic is not a good look, and not a helpful feature.
Image 1: Straps on a 38G bra vs. straps on a 32B bra by Heidi Klum
Another aspect that is sometimes overlooked during grading is the need for sturdier fabrics. Stretch-lace bra cups are so pretty, comfortable, and delicate-looking, but they just don’t work for larger cup sizes. Cute stretch lace bras that come in my size are like roller coaster rides; they start with joy and excitement and end with immediate disappointment upon trying them on. It often feels like wearing a crop top with an underwire. When materials are sturdier, bras are more supportive.
Image 2: This Fantasie bra, designed specifically for larger cups, uses a floral lace that is bonded to a sturdy mesh for extra support in the cup.
Side slings are a small but important addition. Slings are those strips of fabric on the inside of a bra that stretch across the bottom outer corners of the cups. They help lift the tissue up and out, and can be the difference between a bra that has decent lift and a bra that is shockingly comfortable, very supportive, and provides a narrow silhouette.
Image 3: A Gossard bra sized 30B is unlined and sling-less, while the same bra in a 30G has a sling added for more support.
If you have ever worn a bra in a larger size with a thin plastic underwire, you know how important more rigid wires are. One more reason that it’s not enough to simply grade a pattern up evenly: breasts don’t get larger evenly. Larger breasts have more projection, and need more space because of it.
Which brings us to perhaps the most important aspect of a full-cup bra: specially-developed patterns. Since many sizes share cup volume with one another, an easy way to make a bra in an extended size (and what I assume many brands do) is to simply grade up, or scale up, a pattern.
But even if the calculations for breast volume are correct, larger breasts on a smaller frame require different shapes for the best support.
A pattern change isn’t typically noticeable. However, when a brand just can’t get a bra to work at larger sizes, they’ll sometimes change the style from a demi cup to a full cup past a certain size. In those cases, the bra just won’t be supportive for larger sizes in the original shape, so the design team makes the decision to alter it. It can be confusing and frustrating to try on a cute demi bra, only to find that your size has much more coverage. However, the support wouldn’t be there otherwise.
Image 4: These two Montelle bras have essentially the same “look” but are technically two different styles; the top is a demi bra available in core sizes, and the bottom is a full cup bra that comes in a range of larger sizes.


















