• The Cotton One in white, pink and black - cotton training bras for girls, shown flat
  • The Cotton One in white on a hanger - wire-free cotton training bra for girls
  • The Cotton One in soft pink on a hanger - wire-free cotton training bra for girls
  • The Cotton One in black on a hanger - wire-free cotton training bra for girls
  • Cotton - breathes all day, kind to sensitive skin
  • Soft removable pad sliding out of the side opening of The Cotton One
  • The Cotton One size guide: S 44-66 lb, M 66-88 lb, L 88-110 lb, XL 110-132 lb

The Cotton One

The Cotton One

 (388 Reviews)

Four sizes: S, M, L and XL.

Sized by weight, not age — two girls the same age can be built completely differently. Weigh her, find her band, done. No tape measure, no cup sizes.

S
Her weight
50–66 lb
22.5–30 kg
M
Her weight
66–83 lb
30–37.5 kg
L
Her weight
83–99 lb
37.5–45 kg
XL
Her weight
99–121 lb
45–55 kg

Between two sizes? Size up. The knit has a lot of stretch, and a bra that feels tight is the one she stops wearing.
The Cotton One in white, pink and black - cotton training bras for girls, shown flat

The Cotton One

$29.00
$29.00 $58.00
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  • files/gently-review-priya.png

    She put it on and didn't mention it again — which, with a ten-year-old, is the highest praise available.

    Megan R.
  • files/gently-review-danielle.png

    Finally something that isn't just a tiny adult bra. Actually built for her age.

    Danielle K.
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    Nothing on the box says what it is. She opened it herself and was thrilled.

    Priya S.

    Her first bra shouldn't feel like a big deal. This one is soft, seamless and quiet enough that she can put it on, forget about it, and get on with her day.

    • Completely seamless — nothing digs in or shows under clothes
    • No wires, no removable pads, no scratchy tags
    • Double-lined front for full coverage under a school shirt
    • Wide, flat straps that don't slip or cut in
    • Four-way stretch, so it still fits through a growth spurt
    • Machine washable and holds its shape

    Most bras that fit a ten-year-old are adult bras made smaller. This one was designed for her body from the start.

    Fabric: 65% Nylon, 35% Spandex — brushed for softness, four-way stretch.

    Care: Machine wash cold on a gentle cycle. Hang dry. No bleach, no fabric softener, no tumble dryer — heat is what kills stretch.

    View full details

    Made for a body that's still changing

    Not an adult bra made smaller. Every part of this was decided for a girl who is still growing, and who mostly just wants to stop thinking about it.

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    Grows With Her

    Four-way stretch knit that moves as she does, so one size lasts through a growth spurt instead of a month.

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    Double-Lined Front

    Full coverage under a school shirt — with no removable pads to shift, bunch, or vanish in the wash.

    waves
    Completely Seamless

    One smooth piece of fabric. Nothing to dig in, nothing to leave a red mark.

    do_not_disturb_on
    No Wires, No Tags

    Nothing rigid, nothing scratching the back of her neck. She'll forget it's on.

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    Plain packaging

    Nothing on the label says what's inside. She can open it herself.

    Sizing a first bra is genuinely hard, especially for a body that changes month to month. If we get it wrong, that's ours to fix — not yours to live with.

    See the size guide

    THE VIRAL GENTLYWEAR BRAS

      Not just a smaller adult bra

      Most bras that fit a ten-year-old are built like adult bras, only smaller. This one was designed for her body from the start.

      See the size guide
        A regular bra
      Completely seamless — nothing digs in
      No wires, ever
      No removable pads to shift or fall out
      Tagless — nothing scratching her back
      Sized by her weight, not by age

      FAQs

      Go by her weight — it's the one number you already know. No tape
      measure, no cup sizes, nothing to measure against her chest.

      S 50–66 lb (22.5–30 kg) · M 66–83 lb (30–37.5 kg)
      L 83–99 lb (37.5–45 kg) · XL 99–121 lb (45–55 kg)

      It's genuinely seamless — the edges are laser-cut rather than hemmed, so there's no stitching, no elastic ridge and no hardware anywhere to press a line through a t-shirt or a school shirt. Nothing to see and nothing to catch.

      It's built to disappear. No wire, no clasps, no sliders, no adjusters. The straps are wide and flat instead of thin, so they don't dig or roll. There's no tag — the size and care details are printed straight onto the inside back. If she's sensitive to textures and seams, this is the part that matters most.

      65% nylon, 35% spandex — a smooth, lightweight, high-stretch knit. Machine wash cold with like colors. Because the pads are sewn in and there's no hardware to snag, it comes out of the wash the same shape it went in.

      • Processing: 1–3 business days after you order.
      • Delivery: 7–16 business days after it ships.

      Usually you don't decide — she does. Most moms order the first one because she asked, or because she's started folding her arms across her chest. There's no age it's supposed to happen at. If she wants something on, she's ready, and this is the softest possible place to start.

      What mothers tell us

      • She put it on and didn't mention it again

        Which, if you have a ten-year-old, is the highest praise available. She'd been refusing anything with a wire for months. This one just… worked. Ordered two more colours the same week.

        Megan R. · verified buyer

      • Finally something that isn't a tiny adult bra

        Everything I found was either a crop top or a shrunken push-up. This is actually built for her age. The double lining is exactly the coverage I wanted under her white school shirt.

        Danielle K. · verified buyer

      • The packaging matters more than you'd think

        I ordered it to arrive while she was at school so I could give it to her privately. Turned out I didn't need to — nothing on the box says what it is. She opened it herself and was thrilled.

        Priya S. · verified buyer

      • My daughter's first bra

        My daughter's first bra — what a rite of passage. She was worried about it being uncomfortable, showing through her clothes, and basically thought all eyes would be on her. She's been wearing the Day To Day Seamless Bra and has no complaints. It does not show through, no 'outline' with any of the shirts she wears. There's no messing with straps falling or digging into her shoulders. It's also comfortable enough that she forgets about it. We are very pleased.

        Anna L. · verified buyer

      • Exchanged for free, no drama

        Got the size wrong first time, entirely my fault. Emailed them, had a label within hours, and the replacement arrived before I'd even posted the first one back.

        Christina M. · verified buyer

      • She picked the purple and wears it every day

        I'm washing it constantly because she refuses to wear the others. Good problem. It's held its shape through about twenty washes with no stretching out.

        Rachel T. · verified buyer

      • She said it feels like nothing

        Direct quote. She's sensitive to tags and seams — we cut labels out of everything — and this one hasn't come up once.

        Jess W. · verified buyer

      • Bought for my youngest, ended up buying both

        My eldest saw it and wanted one too. They're four years apart and both sizes fit properly, which says something about the range.

        Laura B. · verified buyer