A Guide to Bra Band Elastic: Stretch & Recovery

A Guide to Bra Band Elastic: Stretch & Recovery

If there’s one thing I wish every bra maker understood sooner, it’s this:
the band does the heavy lifting – not the straps.

And at the heart of every good bra band is one quietly powerful component: bra band elastic.

Two elastics that look nearly identical can behave very differently once sewn into a bra. One may feel supportive and stable; the other may stretch out, ride up, or feel oddly unsupportive. The difference usually comes down to stretch and recovery – and once you understand those two things, bra fitting starts to feel a lot less mysterious.

Pull up a chair. Your Fairy Bra Mother is about to explain.

What Is Bra Band Elastic (and Why It Matters So Much)?

Bra band elastic is applied along the lower edge of the bra band (and often the upper edge as well). Its job is to:

  • Anchor the bra to the rib cage
  • Provide horizontal tension for support
  • Help the bra maintain its shape during wear

Unlike waistband elastic, bra band elastic must balance firmness, comfort, stretch, and longevity. Too soft, and the band creeps upward. Too firm, and the bra feels like it’s holding a grudge.

Guide to bra band elastic stretch and recovery 1

This is why elastic choice has such a profound effect on fit — sometimes more than the pattern itself.

Why Stretch Percentage Changes How a Bra Feels

Elastic stretch determines how much tension is created when the bra is worn.

If an elastic stretches easily, the band will feel looser unless it’s adjusted. If it stretches very little, the same band length can suddenly feel tight or restrictive.

This is why:

  • One bra feels perfect
  • The next feels “off”
  • And the pattern is unfairly blamed

(Justice for the pattern, please.)

Understanding stretch percentage lets you predict how an elastic will behave before it ends up stitched into place.

How to Measure Bra Band Elastic Stretch

You don’t need special equipment – just a ruler and a moment of attention.

Step-by-Step Elastic Stretch Test

  1. Cut a 10 cm (4 inch) length of elastic. I often use 10″ (25 cm) when on camera.
  2. Measure it with no tension
  3. Stretch it until it feels firm but not strained (I call this ‘resistance”)
  4. Measure the stretched length

Calculate Stretch Percentage

(Stretched length – relaxed length) ÷ relaxed length × 100

Example:

  • Relaxed: 4″ (10 cm)
  • Stretched: 6″ (15 cm)

That elastic has 50% stretch.

Guide to bra band elastic stretch and recovery 2

Common Stretch Ranges for Bra Band Elastic

Stretch %Typical Feel
30 – 40%Firm and supportive
40 – 50%Medium-firm (most common)
50 – 70%Soft and flexible

There is no “correct” stretch — only what works for a particular body, fabric, and design.

Stretch Alone Isn’t Enough: Meet Elastic Recovery

Now here’s where many sewists get tripped up. Elastic recovery is how well elastic returns to its original length after being stretched. An elastic can stretch beautifully… and still be a poor choice if it doesn’t recover well.

Quick Recovery Test

Stretch the elastic firmly for a few seconds, then let it go.

  • Snaps back immediately? Good recovery.
  • Looks a bit longer or wavy? Not so good.

Poor recovery often leads to bands that feel fine at first — and noticeably looser after a few wears. And no one enjoys a bra that loses enthusiasm halfway through the day.

Why This Knowledge Changes Everything

Once you start measuring elastic stretch and paying attention to recovery:

  • Bra fit becomes more consistent
  • Pattern results make more sense
  • You stop blaming yourself (or the pattern)

You’re no longer guessing — you’re making informed choices.

And that, my dear sewists, is where bra making becomes far more satisfying.

My next post will explain more!

You can watch my practical demonstration on elastics in this video.

Beverly Johnson, your Fairy Bra Mother

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