Designer and United Colors of Benetton artistic director Jean-Charles de Castelbajac has a lot to talk about right now.

This week, the 50-plus-year fashion design veteran, known for the infamous Kermit the Frog coat worn by Lady Gaga and that furry coat made out of teddy bears, is celebrating the launch of a colorful new swimwear collaboration with luxury French swimwear and ready-to-wear brand Vilebrequin. It will be sold online, at select Vilebrequin stores and at luxury NYC boutique The Webster. It’s the designer’s first foray into bikinis and bathing suits, but a challenge he said he was excited to take on.

Castelbajac has also spent the last few weeks being very outspoken on Instagram about designers and brands copying his iconic designs, from a pair of color loafers from Pharrell’s capsule collection with Chanel to a three-hooded sweatshirt from Kith and Russell Athletic. Glossy sat down with the designer to get his thoughts on what it takes to create a successful collaboration, how to find the right collab partner and why so many people are copying his style.

Where did you find your inspiration for this collection with Vilebrequin?
If you know a little of my work and my story, it’s been always very linked to art. My fashion was very inspired by art. I think today, it’s more fashion is inspiring my art. I wanted to do something that would not be what it seems. I designed this black bikini over another one, so it would look like you’re seeing double. Then I did this one piece with a rainbow coming out of it, and I love it, because it’s a reference to the Amazon. I love this idea of a big rainbow coming out of the dark. At the end, what you want to propose is the woman becoming a curator of her own style. It was more about style than about fashion, anyway.

What do you look for in a partner when you think about collaborations?
I have continually been practicing co-branding, not just putting two brands together. When I did collaborations in the past, with brands like Max Mara, it was always the idea of bringing in part of my universe, composed of good design, color, storytelling and style. Then the brand has to bring its DNA, its adventure and the way they are thinking about their own style. This is what excites me. It’s how those two things are confronting, even if they are in totally opposite universes. This collaboration is a couple. There’s a story of seduction, but it’s not exactly this idea that everyone today has to propose a capsule collection, which is just brand-on-brand. Me, I have an old-school point of view of collaboration.

A lot of collaborations today seem so forced. Why do you think that happens so often?
Mais bien sûr. I achieve my worth when you cannot know what is Vilebrequin and what is Castelbajac — it’s the total fusion of things. It’s not to impose my world. Very few people have the capacity to do a perfect collaboration. The very talented Karl Lagerfeld, he was doing it so well at Chanel, at Fendi and at other brands.

Why is the perfect collaboration so hard to achieve?
Well, because you have to avoid your ego. You have to be particularly humble to achieve that. When I designed in 1974, I was not thinking about what I was going to post on Instagram. I was not thinking about the digital consequence of my act. I was not thinking who is going to wear the stuff I made. I was just thinking: I want to create a revolution. I want to be like Jimmy Page on stage — I want to be a rock star or a hero. Today, it’s interesting, because in the digital world, digital is like the door in “Alice in Wonderland.” You open it, and you don’t know where to go. So you have to be very disciplined and very in control, and never give marketing the chance to cannibalize your work. 

You recently posted on Instagram about designers and collaborations (like Chanel and Pharrell) copying your work. Is that just the cycle of fashion or more than that?
I have been copied a lot. I think it’s two things: It’s the rhythm of production and it’s also huge laziness. It’s a fear of the future. If you think about artists taking a song from another artist and doing a cover of that song, sometimes I prefer the reinterpretation. I’m not against that. What I don’t like is the kidnapping of work. If you take an idea from another one, and I have done that, you have to marinate and then transform it. To propose another version, this is the beauty of things. But at this point, I am surprised that very few creatives do this. I understand some companies in the mass market have limits, but somebody creative? Why? Call me, and we can do a collaboration.