What were your initial impressions when you received the project brief for TRAVEL TUMBLER?
I remember clearly that it was my first project after returning to Japan from London. At the time, I had a strong desire to take on challenges that could only be done in Japan, or hadn’t been done here yet. When I heard the brief was for a vacuum insulated stainless steel tumbler, I immediately thought about the importance of detailing, especially where resin and stainless steel components meet and how they are molded together. As a designer, I can’t help but pay attention to the fit and finish of screws and structures. From that perspective, I felt there was still room to explore new ideas and bring something fresh to this category of product.
Where did the design inspiration come from?
In both Europe and Japan, I sensed a pressure that products meant to be touched must have a gentle and friendly look. But I wanted to challenge that notion and show that a design can be both sleek and easy to use, without necessarily being rounded. I didn’t want “non-rounded” to equate to “rough.” My goal was to combine a clean, straight-lined form with a sense of elegance.
What inspired me was the classic milk can used in dairy farming. These are made by bending sheets of metal, which naturally results in a straight, cylindrical shape. I was drawn to that boldness. In a time when any shape is possible, I wanted to revisit the beauty of simple forms that have a sense of clarity and a dignified presence.
In a time when any shape is possible, I wanted to revisit the beauty of simple forms that have a sense of clarity and a dignified presence.
Could you tell us more about the details you focused on?
At first glance, it looks like a simple combination of straight lines. But everything, from the placement and angle of the curve to each proportion, was carefully refined to arrive at what felt like the best possible form. For example, with the lid, we explored how sharp the edge could be while still feeling comfortable to the touch. Together with KINTO and the factory, we worked to strike a balance between a smooth feel and a sleek silhouette.
I also wanted the inside of the lid to look beautiful when opened. Instead of exposing the drinking hole directly, I proposed a structure that hides them within grooves, allowing the drink to flow out smoothly. This approach borrows from the kind of subtle detailing you sometimes see in ventilation slits of electronic devices.
The slight angle at the base of the tumbler was designed not only to evoke the familiar shape of a canned drink, but also to give the tumbler a lighter appearance, fitting for something meant to be carried around. It also serves as a kind of guide when placing the tumbler into a drink holder.
This project involved repeated trial and error and close collaboration with KINTO to realize a shared vision.
Everything from the placement and angle of the curve to each proportion was carefully refined to arrive at what felt like the best possible form.
When and how do you use the tumbler?
I often use it when commuting to the university. I brew pour over coffee at home and take it with me in the tumbler. If it runs out, I get a refill at a coffee shop. I use it regularly, and that lets me evaluate how it actually feels to drink from and clean. I’m especially fond of the lid’s shape. It fits well in the hand, with a comfortable thinness, angle, and grip. The defined edge makes it easy to hold firmly with just a little pressure. It’s a shape that makes sense.
How do you reflect back on this project?
With KINTO projects, I always design to create something I myself would truly want to own. It should also be something I’d want to use every day—because if it’s inconvenient to use, it won’t become part of a daily routine.
For me, product design only gains meaning when it’s used. Through use, the relationship between people and objects is formed, and the product becomes complete. I want to design products that captivate you at first glance, and grow on you the more you use them. With the TRAVEL TUMBLER, I feel I came close to that ideal.
Shin Azumi Product Designer
Established ‘a studio’ in 2005 in London, UK. His design works include consumer products, furniture, lighting, electronics and audio equipments as well as spatial design for shops, restaurants, and exhibitions. Since 2016, he is taking the professorship at Hosei University, Faculty of Engineering and Design, in Japan.
*This interview was originally published in 2021 and has been partially revised and reorganized for this reissue.