A few years into her job as head of brand creative at Kate Spade New York, Theresa Canning Zast had an idea for a complementary brand based on the “feeling of optimism and happiness and the casual attitude of Saturday, the best day of the week.” The look and feel (and price point) would be different enough to not only appeal to a new customer, but to grow the consumer base as a whole.

Then, in 2013, the company gave Zast the official green light to gather a team, design some product, and build the Kate Spade Saturday brand. “It definitely wasn’t that simple, but it was kind of magical. It really just started with a document that was a few pieces of paper with an idea and a little bit of a dream, and we saw potential in it.”

From @KS_Saturday‘s Instagram
From @KS_Saturday‘s Instagram

Before she came to Kate Spade, Zast studied graphic design and photography at Pratt, and did “a number of things out of school” in an attempt to figure out what she really wanted to do. It wasn’t until she landed a job as the style director of Martha Stewart Weddings that she found her calling. “I got to not only ideate what the stories were, but develop the art direction, integrate the type in the story, and oversee it all. We had total control creating everything from the photographs all the way to the layout. I may not have been a graphic designer or a photographer, but I used the skill sets that I know and love.”

An eye for detail and the ability to handle all aspects of production has served her well at Kate Spade Saturday, where an in-house brand creative team of seven does all the design and advertising. “I always say that I don’t know how to work with an agency, because you have to release control. And from the agency side, they create an asset but can’t control how it’s used. That’s a huge advantage to in-house design. I don’t have a client. I get to do whatever I want. It has to be responsible and good for the business, and there are budget constraints, but the good idea wins—period. I might not feel that way if I worked in an office or at a company like Staples, but when you’re telling a lifestyle story you can continue to riff and riff.”

Because the team is small and works closely—both physically in the office space and together on projects—the process is more fluid and less formal. There aren’t grand brand meetings where a direction is chosen behind closed doors and handed down to designers from on high. However, choosing a strong concept at the start of each season is key; then everything, from product design to marketing to in-store design, is iterative.

For Spring 2015, Kate Spade Saturday is taking a sporty, energetic approach—with influences from ‘60s mod and ‘90s athletic wear that’s evident in the strong cuts and bold color-blocking—and even extends to an equally bright and cheery collaboration with New Balance. This defiant sense of optimism isn’t just a carefully crafted message or some clever put-on—it’s bolstered by an enthusiasm for the brand that’s shared by everyone who works for it. Really. After chatting with the in-house team (over lemonade and cookies, what else), you get the sense that while they all seem to be working their asses off, they genuinely enjoy what they do. The latest example of this kind of brand authenticity is the addition of a new logo to the company’s growing “kit of parts.” Called “6 XO,” it represents a full calendar week with Saturday highlighted in a yellow circle, another reminder that Saturday isn’t only the best day of the week, but it might just have some of the best in-house designers you’re likely to work with in fashion.

Photographs by Nicholas Prakas. This studio visit was organized by AIGA/NY as part of “GAIN: AIGA Design and Business Conference.” For more information on in-house design, see AIGA’s In-house program INitiative.