What makes brands within our community special is the stories behind them. From dreams come true to sparks of creativity, innovative ideas to parents seeking something the market has yet to offer, and deciding to provide it themselves. In celebration of the mother behind it all, let’s learn more about the brand Cos I Said So and how it came to be such a standout in the kid’s fashion industry.


When Belgian Sofie Ysewijn became a mother in 2014, she uncovered a desire to start her own children’s brand. With a background in the sales and marketing side of the fashion industry, she found herself seeking to channel her creative side more in 2016. Back then, she had a hard time finding clothes for her kids that she really liked. Sofie prefers kid’s clothing with an adult style vibe that is adapted to children. So, she decided to create Cos I Said So to bring cool, comfortable, unisex clothing to the kid’s market.

Starting Cos I Said So was about more than filling a need in the kid’s market. Sofie started it mainly to make something all her own. She wanted to create something for herself, to design clothing and start her own company, on her own terms. This would also allow her to balance her work and personal life better than her previous jobs, giving her more time with her kids that inspired it all. For the name, Sofie drew inspiration from children’s natural curiosity. The most common answer parents can offer to kid’s frequent questions of “Why?” is “Cos I Said So”! She loves that sometimes, things just are as they are, for no real reason. Many of the first garments also featured quotes, which fit well with “Cos I Said So.” Overall, Sofie wanted to create a brand with a message.

cos i said soFUNKY TOWN, AW23-24

For the very first collection, Sofie kept things super basic. She wanted the designs for this collection to be seasonless. So, it was centered around a minimalist, unisex aesthetic. Using grey, black, and white, the graphics and quotes were center stage. Happy Human was her first print, and remains the best-seller to this day. The taglines and quotes were very popular when this collection was released, so Boy & Girl Gang items sold well, too. This first collection was, of course, a trial run. Sofie was cautious, seeking to test the waters first with a small collection to see how it would be received. Since this collection, Cos I Said So has grown organically. It has expanded following the rhythm of Sofie’s own life and energy. She never wanted to chase huge growth that would sacrifice the “life” part of the work/life balance.


Cos I Said So, from the beginning, has been a unisex brand. Sofie does this as one way to be sustainable, since unisex clothes give garments a longer life. They can be passed on from gender to gender for generations. The unisex aesthetic is also in line with her own personal tastes. Sofie herself doesn’t like to dress very girly, and knows that there are many little tomboys out there that don’t want to either! There are also many boys that don’t want to dress in “typical” boys clothing. In her opinion, a good basic is very gender neutral. Colors, too, are free of gender.

As a mother of two boys, Sofie thinks that boy’s fashion has historically been more limited, as there are less items in the market that are “boy-proof”. As the kid’s fashion industry has developed and changed over the years, Sofie has found that it has become more openminded to colors and prints being used for boys, too. One of the core values of Cos I Said So is that all children should dress in a way that makes them feel comfortable and confident. If that means bright colors for boys, go for it! In today’s market, it’s an idea that’s more generally accepted. On the contrary, Sofie struggled a bit at the start of Cos I Said So with creating clothing that was a bit more for girls, since her sons were her muses.

She has always found both boy’s clothing and basics the most cool and interesting. As the brand has grown and matured, the collections get both bigger and wider each season. Sofie has started putting more design focus that would appeal to girls as well, hoping to bring a good, even mix to Cos I Said So, so that both boys and girls can find what they want in her collections.


Designing the collections to be unisex is just one of the many ways Cos I Said So is being sustainable. Having worked many years in the fashion industry, Sofie recognizes that fashion is an undeniably polluting industry. For her, sustainability has to be incorporated into the entire process to be meaningful. It’s about doing our best at every link in the chain. For this reason, Cos I Said So collections are ethically produced in Portugal. Everyone that works on them does so in a safe work environment, for a good wage. They use biodegradable polybags to ship their items. Wherever they can, Cos I Said So uses organic and sustainable fabrics, and produces only what is sold or that Sofie knows will sell. They avoid mass production, and only produce two collections per year.

By using high quality materials and processes, Cos I Said So collections can last a long time. They are durable enough to be passed down from generation to generation, from boy to girl and vice versa. By printing very few catalogs and focusing as much as possible on digital communication, they try to keep waste down, too. They reuse cardboard boxes and group online orders when possible. Every little bit helps, which is why Cos I Said So is doing their best at every step.

cos i said soFUNKY TOWN, AW23-24

For Sofie, the thing that she thinks makes Cos I Said So unique in the market is that it evolves along with her. Her creative mind is behind the designs for every collection. Each season, the theme, colors, and graphics start in her thoughts, evolving with her life, moods, and experiences. Her team in Portugal then helps her bring these concepts to life. Just as every individual is unique, Cos I Said So is inherently unique as well. The brand is constantly developing and growing along with Sofie’s creativity, bringing a vibe and experience in addition to the clothing itself.

Over the years, there has been plenty of growth. One big step for her and Cos I Said So was the transition from heatpressing prints by hand to incorporating this into the production process. For the first few seasons, Sofie’s own hand heatpressed each print, so this development made life a lot easier! Expanding from storing stock in her garage and working from a spare room to having a beautiful office in Antwerp has been another great, big step! Three seasons ago, Sofie took the entire production process to Portugal. This big shift allowed her to manage the quality and production better. Participating at the Playtime & Kid’s Hub trade shows has also opened a lot of doors for Cos I Said So.

At The Big Small Show, Sofie has been able to meet a lot of interesting buyers and fellow professionals. This has really helped her to put Cos I Said So on the map. Playtime Paris was the first trade show Sofie ever exhibited at. She returns each season because it is a great place to see people again that she has established a relationship with. Sofie also feels it’s THE show to be at for the kid’s industry in Europe. Last summer, Sofie took a new, bigger step, and exhibited at Playtime & Kid’s Hub New York as well. This experience was really interesting for her, leading to meetings with new retailers and writing some good orders. She will be back this winter on February 11-13 to further build Cos I Said So’s presence in the United States, and maybe find a U.S. agent.


For me, Paris is a show I always need to be at it. I’m doing the New York show again to see what the Winter show is like. This will help me analyze both seasons, which I think is very important.


One of the biggest moments Sofie has had so far at The Big Small Show was when the retailer Smallable placed orders for the first time on her AW23 collection. While every order is confirmation her brand is desirable in the kid’s market, this order from Smallable gave Cos I Said So global visibility and credibility. The shows have also helped lead to her working with agents: AB Fashion Agency for Belgium, M-Agency for the Netherlands, and Little Wander for France, Austria, China, South Korea, and the Middle East. By using agents, Sofie is able to focus more of her time on creating the collections. With the amount of time and work that goes into each step of the process to create and run a kid’s brand, it’s great help for Sofie to delegate whenever possible. Her team also supports and assists her with the brand’s growth and development.

cos i said so - Playtime ParisCos I Said So booth at Playtime Paris, Winter 2023
cos i said so - Playtime & Kid's Hub NYCos I Said So booth at Playtime & Kid’s Hub NY, Summer 2023

Step by step, Cos I Said So has expanded from collections made up of t-shirts, joggers, and sweatshirts to including more silhouettes and styles. The basics remain at the heart of the brand’s DNA, and its best-sellers. The sizing has also expanded to cover all children, from babies to teens. Over the years, the processes have become smoother. Sofie has learned from every challenge and mistake to make Cos I Said So a little better with every step. To her, growing also includes perfecting the supply chain. Not only getting bigger, but getting better at what they already do.

For her Autumn-Winter 2023-2024 collection, Sofie wanted to create a funky, urban vibe. Hence the name of the collection, “FUNKY TOWN!” The photoshoot was done in her hometown of Antwerp, celebrating its beautiful architecture. The collection is, of course, unisex. With a focus on minimalism, the graphics are based around music, partying, and having a good time. Sofie had heard the classic song “Funky Town” on the radio for the first time in a while, sparking her initial inspiration for the collection. A few days later, she went to see the new Minions movie with her kids, where the song was also featured. She figured the universe had decided already: funky town is the next collection’s theme!


Another big step Cos I Said So has taken was joining our B2B ordering platform, Orderwizz. For a long time, Sofie had been working with different tools for her B2B business, but it was never satisfying or simple. Sofie has found Orderwizz easy to work with, with great and fast assistance whenever she needs it. For her, it’s a really user-friendly platform for both brands and buyers.


It’s like an online trade show, so people can easily get to know your brand and place orders.


For the future of Cos I Said So, Sofie has several goals. She wants to grow her business in the United States and Asia, and is considering exhibiting at the next edition of Playtime Shanghai. Naturally, she wants to continue making good, strong collections. While there is no denying the retail environment is strained by the current global economy, she’s hopeful that this will lead to a slower paced fashion industry that is more mindful. Sofie thinks it’s important for both brands and retailers to assess their pace and take it a bit slower moving forward, for the benefit of our planet and future generations. She would love to do a collaboration with another brand to create something unique for both of them. She is always dreaming of new ideas to grow and evolve Cos I Said So.

Exclusively for Playtime & Kid’s Hub, Sofie has shared a little teaser for the new Autumn-Winter 2024-2025 collection. The next collection will be slightly bigger than the current AW23-24. It will be unisex, but also very versatile. The designs are eclectic, allowing kids to go many different directions with it. In her opinion, it’s a very fun winter collection! For the theme itself, the curious will have to stop by the Cos I Said So booth! Sofie will unveil the surprise and wonder of her new collection in Paris January 27-29, 2024, and New York February 11-13, 2024, so get your pass to come discover it for yourself!

cos i said soSofie, founder of Cos I Said So with her sons

Thank you to Sofie for sharing the incredible success story that is still in progress at Cos I Said So! We can’t wait to see what the future brings this wonderful brand. Buyers can create their free account on Orderwizz to restock with items still available in Cos I Said So’s current AW23-24 collection. They can then stay tuned for Sofie to upload the new AW24-25 collection which will be available for pre-order on Orderwizz and at The Big Small Shows this winter!


All images from Cos I Said So
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Madeline Blankenship
Madeline Blankenship