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Power micromesh is surprisingly supportive [Aube 1]
Triangle cut is low coverage in the front and sides [Aube 1]
Adjustable hook and eye and strap sliders in the back [Aube 1]
Wide elastic bland is comfortable and supportive
Hannah is a 36DD in our size 4 [Hannah 4]
The back of the bra can be adjusted tighter or looser [Hannah 4]
  • Thumbnail image #1 of Sieve Triangle Bra in Black [Aube 1]
  • Thumbnail image #2 of Sieve Triangle Bra in Black [Aube 1]
  • Thumbnail image #3 of Sieve Triangle Bra in Black [Aube 1]
  • Thumbnail image #4 of Sieve Triangle Bra in Black
  • Thumbnail image #5 of Sieve Triangle Bra in Black [Hannah 4]
  • Thumbnail image #6 of Sieve Triangle Bra in Black [Hannah 4]
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Product photo #1 of Sieve Triangle Bra in Black [Aube 1] Product photo #2 of Sieve Triangle Bra in Black [Aube 1] Product photo #3 of Sieve Triangle Bra in Black [Aube 1] Product photo #4 of Sieve Triangle Bra in Black Product photo #5 of Sieve Triangle Bra in Black [Hannah 4] Product photo #6 of Sieve Triangle Bra in Black [Hannah 4]

Sieve Triangle Bra

Rated 4.4 out of 5
Based on 820 reviews

Surprising support. Deep v neckline.


Our signature Sieve mesh in a lower coverage triangle cut. Great shape - no pad or wire included. 
NEW

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Free U.S. shipping on orders over $100. Easy returns.

Fit

  • Size Chart
  • Use this as a guide. Preference is a huge factor — the benefit of a non-wire is they're super flexible, so you will likely fit in more than one size. Like a looser band? Size up! Like less coverage? Size down! Still unsure? Try two sizes :)
  • Adjustable straps and hook & eye closure in the back
  • *Note, our Sieve Triangle Bra is an intentionally lower coverage in both the cups and the sides. Wide plush elastic band is extremely adaptable.

Fabric + Care

  • Size Chart
  • Made from a sheer Belgian power micromesh — nipples are visible
  • 74% Polyamide (Nylon) 26% Elastane (Spandex)
  • Wireless
  • Hand wash in cold water, dry flat

FAQ

  • All full-priced, unworn items, with tags attached and in their original packaging are eligible for return or exchange within 30 days of placing your order.
  • Please note, packs must be returned in full. We do not accept partial returns of packs.
  • Want to know our full returns policies? Here you go.
  • Want more info about shipping, materials or care instructions? Here!

    Q’s on fit or sizing? Email us at hello@negativeunderwear.com

Pair it with ->

Sieve High-Waist Brief in Black Sieve High-Waist Brief in Black Sieve High-Waist Brief in Black $45 +
Cotton French Cut Brief in Black (Pack) Cotton French Cut Brief in Black (Pack) Cotton French Cut Brief in Black (Pack) $58 +
Whipped Boy Short in Black Whipped Boy Short in Black Whipped Boy Short in Black $45 +
Essaouira Thong in Black Essaouira Thong in Black Essaouira Thong in Black $30 +
Write a Review
average rating 4.4 out of 5
Based on 820 reviews
  • 5 Stars
    573 Reviews
  • 4 Stars
    97 Reviews
  • 3 Stars
    83 Reviews
  • 2 Stars
    44 Reviews
  • 1 Star
    23 Reviews
87% of reviewers would recommend this product to a friend
Overall
Rated 0 on a scale of minus 2 to 2, where minus 2 is Hated it, 0 is Meh and 2 is Loved it
Quality
Rated 4 out of 5
Comfort
Rated 4 out of 5
820 Reviews
Reviewed by Elizabeth D.
Verified Buyer
Review posted
Sieve Triangle Bra in Black
Reviewing
Sieve Triangle Bra in Black
I don't recommend this product
Rated 3 out of 5
Size Purchased
2
How it Fits
True to Size
Age Range
55 - 64
Bra Size
34B

Mixed feelings

I love the idea of the sieve underwear line. I really do. They fit well. The bra does fit perfectly and does it's job flawlessly.

But, I really don't like touching the fabric. It is not soft. once it is on it feels sort of ok but when I look at it in the drawer and know I have to touch it I steer away. I am very fabric sensitive...

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Overall
Rated 0 on a scale of minus 2 to 2, where minus 2 is Hated it, 0 is Meh and 2 is Loved it
Quality
Rated 4 out of 5
Comfort
Rated 2 out of 5
Was this helpful?
Reviewed by Thomas
Verified Buyer
Review posted
Sieve Triangle Bra in Buff + White
Reviewing
Sieve Triangle Bra in Buff + White
I recommend this product
Rated 4 out of 5
Size Purchased
2
How it Fits
A Little Small
Age Range
45 - 54
Bra Size
32DD/E

Cute, sexy bra

Fits small in cup and worried that with s next size band will be too big.

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Overall
Rated 1 on a scale of minus 2 to 2, where minus 2 is Hated it, 0 is Meh and 2 is Loved it
Quality
Rated 4 out of 5
Comfort
Rated 3 out of 5
Was this helpful?
Reviewed by B S.
Verified Buyer
Review posted
Sieve Triangle Bra in Navy
Reviewing
Sieve Triangle Bra in Navy
I recommend this product
Rated 5 out of 5
Size Purchased
4
How it Fits
True to Size
Age Range
35 - 44
Bra Size
34DDD/F

I’m (pleasantly) surprised..

With my measurements, I wasn’t expecting this to work for me— but I actually really like it! Makes me feel free but not so free that I don’t feel supported (need Some kind of support). Seems very well made too. It’s new so we’ll see how well it holds up.

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Overall
Rated 1 on a scale of minus 2 to 2, where minus 2 is Hated it, 0 is Meh and 2 is Loved it
Quality
Rated 4 out of 5
Comfort
Rated 4 out of 5
Was this helpful?

Non-Wire Bra Sizing

Non-Wire Bra Sizing Size Chart

* Non-wire bra sizing can vary by preference and if you're toward the top of a size range and prefer more coverage, you may want to size up. For styles available in + sizes (designed with additional support details for our larger cup customers), we find DD's can be on the cusp - if you prefer more coverage and support, we suggest the + bra equivalent for your band size.

Btw, the size nomenclature has changed for Bra Tops. Here's the conversion:
XS=0, S=1, M=2, L=3, XL=4, XXL=5

Q’s about sizing or fit? Email us at hello@negativeunderwear.com

@negativeunderwear