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Customize Your Fit with Underwire Adjustment » All bra adventures


Customize Your Fit with Underwire Adjustment

Recently I picked up the Freya Fancies Plunge and Cleo Marcie and felt that while the size I purchased was the correct size for me, the cups pulled in a way that was unflattering. These two bras had opposite problems: Fancies has a very deep J shaped underwire, while Marcie's underwire is wok-shaped and shallow. Because of these underwire shapes, the resulting fit was what I'll call a "tissue distribution mismatch" on me and resulted in areas of drag lines and wrinkling. Since I really liked both styles, I wanted to make them work, and with a little bit of underwire adjustment, they did! I'd like to share my experience and tips and hopefully this is helpful for others to get a better custom fit on your bras when sizing up or down doesn't help.

Note: this suggestion is about making super minor shape adjustments to your underwire that will improve fit. I do not suggest trying to make big measurement changes to your underwire as that can structurally mess with the wire! As MamaPagan suggested below, you’d be better off changing out the underwires if you want to make a big change. I just want to demonstrate that very small shape changes can help improve your bra fit significantly without altering the measurements— when I altered Marcie, there was no change to the cup width, just a slight shape correction :)


What is "tissue distribution mismatch"?
This is when the shape of the bra cup pushes your breast tissue in the wrong places although the overall volume of the cup size is correct. When you pull the cup over the breast gently, it should be smooth and appear to be the correct fit, but when you let the bra rest naturally, wrinkles and drag lines appear. By changing the shape of the underwire, you can change the proportions of the cup slightly so that it better aligns with your natural shape.

What are drag lines vs wrinkles?
These are commonly confused, but are two opposite phenomena. Wrinkles occur when there is excess fabric and not enough tissue to fill it. Drag lines occur when there is not enough room in the fabric and the fabric doesn't have the appropriate degree of stretch to accommodate the tissue, so it ends up pulling in the direction of whatever natural stretch is present in the fabric (typically along the bias of a woven fabric). Areas will drag lines will be TIGHT and straight, while areas with wrinkles will be LOOSE and baggy.

How to tell if my bra is a good candidate for underwire adjustment?
- First, make sure the bra cup is the right size for you. Check the measurements of the cups against a similar bra that fits you (width x depth x height should give you an approximate cup volume), or check the depth of the cup and make sure it's relatively close to your horizontal breast measurement.
- Pull the fabric of the cup gently over the breast and make sure it lays smoothly and looks right. If you have to pull too much and the fabric ends up covering a lot more of the breast than it's supposed to, it's probably too large. If there's no room to pull the cups, they are probably too small and this method won't work to improve the fit.
- If the above improves the fit and you are pulling fabric outwards (horizontally), you will want to open up the underwire shape.
- If the above improves the fit and you are pulling fabric upwards (vertically), you will want to deepen the underwire shape.


Step by Step:
1) Check to make sure the bra is a good candidate for adjustment, see steps above :)

2) Compare the bra's underwire shape to the underwires of a bra that fit you well. Understanding what you want your final underwire shape to look like will help you adjust them correctly.

3) Fold the bra in half and bend the two cups together at the same time. You will only want to make a very minor shape adjustment at this point.
- If the wires are too shallow and you want to bring them together, hold both ends of the "U" shape and gently bring them together in repeated bending motions
- If the wires are too deep and you want to open them up, hold both ends of the "U" shape and gently pull them apart in repeated bending motions.

4) Try on the bra periodically and observe your progress. Bend gently and GO SLOWLY!!!

5) After you adjust the overall shape, focus on any problem areas. For the Freya J curve underwire, I held the middle of the underwire and then only bent the outer part of the wire to open them up.
- Bending the entire underwire too much can distort the fit at the gore, so I'd recommend very minor adjustments overall, focusing the majority of the adjustment on the outer half of the cup unless you have a specific problem with the gore.

6) If the wires end up digging in slightly at the gore while wearing the bra, hold the base of the gore in place with one hand and use your other hand to flex the top of the gore away from your body a few times until it's comfortable.

7) Adjust straps and band as necessary. Remember that widening or narrowing the underwire will change the band fit slightly! Don't be surprised if you have to change hooks after this adjustment.


That's it! I increased the cup width of my Freya Fancies by 0.3 cm each (less than 1/8" inch), but the shape of the underwire became a significantly gentler curve, and the fit has improved dramatically. A seemingly minor adjustment can really help improve the fit of your bras, so I hope this helps anyone who is facing the same issues. Happy customizing!

Filed under Bras ups and downs

Shared on Aug 29, 2019 Flag this


  • Thank you belleandblues ,
    specifically for the GO SLOWLY part.

    Modern underwires have most often a flat profile and are made of slightly hardened spring steel.

    Bending them results in this (I hope the link works):

    I.e. bending momentum on the the thin side results in tremendous mechanical constraints along the large side.

    And the high probability for a "twist" and snap since, be it said, they are originally formed while maleable and hardened to keep their shape.

    Old bra underwires are often used to make lock picks or sharpened to assist in cleaning inaccessible portions of hydraulic valves or or removing inner o-rings.

    Have a glorious day,


  • I’ve never heard of it described as drag lines before. I get those all the time in the middle of the bra. They leave imprints on my skin. 😢

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