Why We Made Peek-Proof

At Understance, we want to make comfortable, flattering bras that meet the needs of everybody, and if there’s one thing that we get asked for the most, it’s T-shirt bras. Whether during product fittings, on social media, or in chats and emails, we get that same request.  

Which is why we’re proud to introduce Peek-Proof, our newest collection. Keep reading to see how we made these perfect everyday T-shirt bras with cutting-edge innovation. 

Peek Proof Understance

The Problem: Making T-Shirt Bras For DD+

T-shirt bras are usually made with molded foam cups. For DD+ cups, T-shirt bras that actually work are extremely hard to find, due to how unforgiving molded foams are. On DD+ cups, traditional T-shirt bras often end up looking like boob hats instead.  

We currently offer a few T-shirt friendly alternatives for larger breasts, made of molded fabric cups and padded seamed cups (for more information about the different types of cups, click here). 

Sidney Bra by Understance
Our Sidney bra on Karen, wearing 36DDD

An example is our Sidney bra. Although Sidney’s cups are smooth, the fabric is stretchy and thin, so it doesn’t offer great nipple coverage. (For T-shirt bras, rigid fabric often works better as it can press nipples down and prevent them from poking through shirts.)  


Zoe Bra by Understance
Our Zoe bra on Lydia (Instagram @styleisstyle), wearing 40DD

On the other hand, our Zoe bra is surprisingly quite T-shirt friendly. Its lace is small, patterned, and rigid which helps hide nipples, but having lace means that the cups are not completely smooth. Zoe is invisible under most shirts, but not thin white T-shirts.


In general (like for Ivy and Salma), we’ve heard that our bras’ side wires are too high and poke into the armpit area (we design our bras with side coverage and side boob in mind), causing some discomfort. If you struggle with this, Peek-Proof is the collection for you. Peek-Proof has lower side underwires, making it friendly to those with short torsos. 

What’s Needed for Nipple Coverage?

We know that unlined bras are the most comfortable to wear, but we also know that padded bras offer the best nipple coverage. However, on hotter days, a padded bra can feel bulky and hot, making you extra sweaty. Our challenge was to find the perfect middle ground. 

Essentially, nipple coverage requires some form of padding. But when thinking about this, we realized that not the entire cup needs to be padded. As long as the nipple part is padded, you get the desired coverage.  

The Solution: Peek-Proof's Cutting-Edge Innovation

Peek Proof Bra Understance

Cups are made with three layers of fabric bonded together, creating one seamless and smooth surface.  

Peek Proof Bra Technology

When touching the cups, the center part where the padding is feels a bit thicker. Unlike traditional foam bras, however, this padding isn’t bulky and it’s actually breathable. 

Using this new technology, we made Peek-Proof, a bra that strikes the perfect middle ground between unlined bras and padded bras. Peek-Proof is partially padded. You have more coverage where you need it and less where you don’t (there, you get the feeling of an unlined bra instead). 

Introducing Our Peek-Proof T-Shirt FlexWire Contour Bra Collection

Peek Proof by Understance

Peek-Proof was made with the latest in bra science. It combines traditional craftmanship with cutting edge innovation to bring you ultimate comfort. 

Peek Proof Understance
  • Fits like your favourite unlined bra, but with better nipple coverage. Wearing it feels like freedom. (Disclaimer: this collection is in between unlined and padded) 
Peek Proof Understance
  • Smooth, seamless, and T-shirt friendly. This bra offers a sleek and flattering silhouette under clothes. 
  • More centered apex (where the straps are attached to the rest of the bra) to prevent slipping shoulder straps 
Peek Proof Understance
  • Our signature comfortable FlexWire™ moves with your body and not against it 
  • Shorter underwire (great for those who struggle with digging on the sides) 

Offered in 3 best-selling Understance styles for optimal fit and style match

Peek-Proof T-Shirt FlexWire Contour Demi Bra 

Our demi style is based off Harper and offers the perfect combination of comfort and coverage. The mesh upper section and satin straps may look delicate, but they do a good job at holding you in. 

Peek-Proof T-Shirt FlexWire Contour Plunge Bra 

Our plunge style is based off Ivy and offers great lift and support. It has a lower center gore (where the underwire meets in the middle), and is a great option for anyone who tends to find the underwire irritating at the sternum. But it’s still fairly full coverage, which provides a secure fit. 

Peek-Proof T-Shirt UniWire Contour Full Coverage Bra 

Our full coverage style is based off Cleo and has no center gore for maximum sternum comfort. The underwire does not curl up in the center at all, but instead goes across the bottom of the bra in one wavy stroke. It has a fabric “center gore,” which provides a little bit of separation and prevents “monoboob.” 

Frequently Asked Questions

1. What bra size am I?

You can find your bra size using our size calculator. It uses a different algorithm for each size range, so each size range can get the perfect match. We consider your breast fullness and prioritize your personal preference. 

We recently wrote a blog post that talks about the fundamentals of bra size, explains why getting the right fit is so important, and provides more information about our calculator. Read it here. 

2. What colour bra do I wear under a white T-shirt?

Choose a T-shirt friendly bra that’s closest to your skin tone. When in doubt, wear a warmer-toned bra instead of a cooler-toned one. A red-ish bra can sometimes be a stand-in nude bra. Darker pinks, burgundy, even a deep purple can be invisible under white, for various skin tones. Make sure to stay away from bright white though – it’s actually one of the least invisible colours under white. 

T-shirt friendly bras are smooth and seamless (no darts or expressive details on the cups), so they look invisible under clothes. You can see some of our T-shirt friendly bras here. 

3. How do I know if my bra fits correctly? What is a nursing vs. regular bra?

First, do the scoop and swoop. It helps your breast tissue sit fully in the cups and eliminates gapping. Then, do a fit check by following this guide. The guide outlines five objective standards of a technically perfect fit that most bra fitters agree on. But bra fit is more art than science. If the bra you’re wearing meets all five standards, but feels stiff and punishing, don’t settle for it. If it doesn’t meet all five standards, but feels right for you, you can continue wearing it. 

4. Why doesn’t my bra fit right?

Make sure that you have done the scoop and swoop. It ensures all your breast tissue is in the cups and eliminates gapping. Watch our video tutorial here. 

If you’re still experiencing fit issues, read through our troubleshooting guide. It lists 12 common fit problems about the band, underwire, cups, and straps, and offers solutions. Once you’ve figured out the issue, use the filters on our website when browsing for the next bra to try. We also have a Comparison Tool that allows you to look at up to three bras side-by-side, in terms of prices, product specifics, etc. 

5. What is the difference between a T-shirt bra and normal bra?

A T-shirt bra is made to be worn under T-shirts. It has smooth cups (often made with molded foam) that look seamless and invisible under clothing. A normal bra could have seams, darts, or expressive details on the cups that poke through.  

Did you know there are four types of bra cups? Molded foam, molded fabric, padded seamed, and unpadded seamed. Learn more about them here. 

1 thought on “Why We Made Peek-Proof”

  1. Thank you, thank you, thank you, Understance, for being so responsive to customers! I have been looking for a bra like this and you created it! Will be ordering one shortly.

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