Last month, Summersalt launched a collaborative line with Rifle Paper Co., resulting in a colorful line of swimsuits in iconic prints from the stationery seller. The collection sold over $1 million in swimsuits in the first 24 hours of launch. And the collection comes on the heels of a big collaboration for Summersalt with Netflix’s popular DIY and home organization show The Home Edit.

Fortune recently chatted with Summersalt’s cofounders—chief brand and digital officer Reshma Chattaram Chamberlin, and CEO and president Lori Coulter—to learn more about how they’ve been able to sustain growth during a pandemic and a new body-positive campaign for the summer.

Courtesy of Summersalt

The following interview has been condensed and lightly edited for clarity.

Fortune: One of the major tenets of Summersalt’s brand is inclusive sizing and body positivity. But that can be easier said in practice than accomplished. What inspired the brand in the first place? What work went into developing Summersalt’s swimwear and subsequent apparel?

Coulter: From the beginning, our goal has been to spread joy. We want to inspire our customers to engage in life and dive in wherever it may lead them. The same joy we felt as children when interacting with the water—uninhibited fun. Swimwear had been marketed in an over-sexualized way for generations. We saw a unique opportunity to change the conversation around swimwear, by delivering designer product without the designer price tag that [the customer] actually wanted, and marketed to her in a way she wanted to be spoken to. Swimwear was ripe for disruption, and Summersalt was the right brand at the right time to revolutionize a tired industry and create a strong connection with the consumer.

Chattaram Chamberlin: Body positivity and inclusivity are at the foundation of who we are as a business. Lori and I both come from varied backgrounds, and we bring our unique perspectives to the foundation of Summersalt. In 2019, we launched our inaugural “Everybody Is a Summersalt Body” campaign and have continued that message through our most recent campaign in 2021, which included women like Jessamyn Stanley, Maye Musk, Sara and Erin Foster, Deepika Chopra, Ali Krieger, and many more amazing women who inspire us all to be confident, happy, and joyful. 

Coulter: From the very beginning, we set out to be a generation-defining lifestyle brand. We began with swimwear, a category plagued with legacy players and lack of innovation. Our advantage around fit—using 1.5 million measurements taken from the body scans of 10,000 real women—allowed us to create significant momentum and a wedge into consumers’ wardrobes. We now offer other apparel categories including sleepwear, intimates, activewear, loungewear, and more that continue to excite our customer and inspire her adventures.

Courtesy of Summersalt

The original Sidestroke one-piece swimsuit (specifically in Seaweed & Seaglass & White Sand) was a viral sensation on Instagram. Handling that kind of runaway success can be daunting for startups, though. How were you able to scale to meet demand? What have been the biggest drivers to Summersalt’s growth? Social media, word of mouth, or something else entirely?

Coulter: We create all of our designs and patterns in house, using our proprietary fit technology. We are able to go from prototype of a new style to completing production in as little as six weeks. Our supply chain operates at warp speed, which is a critical element to being able to scale quickly and deliver on our customer promise. 

Chattaram Chamberlin: The drivers of Summersalt’s growth have been providing our customer with the right product at the right time, with quality, fit, and functionality at the foundation of each garment we produce. We always believe in meeting her where she is, and that means where she is physically, where she is shopping digitally, and what she needs emotionally. This has allowed us to create authentic connection with our customer that has driven powerful customer loyalty and retention. We believe in a 360-marketing approach that allows our customer to discover Summersalt on the platforms where she spends most of her time. 

While we have had great support from press, celebrities, and influencers, the No. 1 sales driver always comes back to word of mouth and customer reviews. Our customers are our biggest advocates.

Courtesy of Summersalt

As Summersalt has grown, it’s also launched a number of limited-edition product lines, most recently with Netflix’s The Home Edit and Rifle Paper Co. How do these collaborations come about? What are you looking for in potential collaborative partners, and what lessons have you learned from previous experiences that you would apply in the future?

Coulter: We start by looking for partners who share our values, who can help us continue to bring joy and positivity into our customers’ experiences. The brands we choose to work with may specialize in different areas, but they all resonate with our customers and have unique perspectives. With The Home Edit, we are able to deliver a truly joyful, colorful collection. And with Rifle Paper Co., beautiful, unique prints that sold out in 24 hours. We always want to create unique experiences for our customers through our product.

Chattaram Chamberlin: Another key value we look for in our partners is cultural alignment from a collaboration standpoint and approach to our customers. Our teams work closely to bring the best elements from both brands to each collaboration, and you can see the joy and passion reflected in the finished product.

Courtesy of Summersalt

Now that many states have surpassed 50% in vaccinating their residents (at least with one dose), summer travel and socializing are coming back in big ways. With that means new clothes, and for a lot of people, new swimwear. What has business been like in the last several weeks? And what was it like over the last year when people weren’t going out or traveling? Were you affected at all? What are you looking forward to most this summer?

Coulter: At the beginning of the pandemic, we had to shift our operations overnight to focus on what our customers needed at the time—loungewear, pajamas, apparel she felt comfortable in. We were able to utilize our supply chain at warp speed and meet her needs during a very difficult time. As we approached summer 2020 and launched our “Summer of Simpler Things” campaign, our customer was ready to explore her backyard, go on safe trips to lakes and beaches, and we were ready to go with her. We had a strong summer last year and were able to return to our pre-COVID goals by midyear.

Chattaram Chamberlin: This year, people are looking to shop and head out on adventures again—adventures bigger and better than last year. Women are looking for garments and swimwear that inspire joy and comfort. We’re able to provide that through our amazing swimwear and apparel collaborations. 2021 is off to an incredible start.