About THE CARD BAG
“I forgot to bring it again.”
We created this bag to make that moment disappear.
Convenience stores, supermarkets, and unexpected shopping trips.
That small regret of having to buy another plastic bag.
You own a reusable bag, but somehow, today was the day you forgot it.
You switched bags and left it behind.
It is a familiar experience for many people.
What we set out to create was a reusable bag you would actually want to carry every day:
one that folds down to card size in an instant.
Ready to use when you need it.
Easy to put away when you are done.
Light and compact enough to carry every day without thinking about it.
But it also had to be more than just small.
It had to be practical, durable, and reliable.
That balance is where our development began.
The Days of Prototyping
The first sample did not fit into card size, even when folded.
The material was too thick. The seams got in the way. The folding method was too complicated.
A tool that takes effort every time you use it will never become something you carry every day.
Through dozens of prototypes, we gradually moved closer to the ideal form.
Our highest priority was making it fold down in an instant.
To achieve that, we reviewed the structure again and again.
We changed the folding sequence.
We reduced the number of parts.
We adjusted the stitch positions by just a few millimeters.
The current form was born from this steady process of refinement.
A Careful Choice of Materials
The greatest challenge was balancing two things:
thinness when folded, and strength when opened.
We tested dozens of materials.
Thickness, weight, durability, texture, and how the material changes with use.
By actually using and repeatedly testing each material, we finally arrived at one we could trust.
Light, strong, and comfortable to use over time.
Resistant to losing its shape, even when folded down to card size.
The details you do not immediately see are where true ease of use is created.
A Mechanism That Folds in an Instant
The heart of THE CARD BAG is its folding mechanism.
The idea itself is simple.
But to make it possible for anyone to fold it quickly, intuitively, and into the same shape every time, every detail had to be carefully designed.
The position of each fold.
The balance of each panel.
The tension and structure of the material.
The result is an original folding structure that fits into card size in just three steps.
At the checkout counter, on the go, or while traveling, it is designed to be used smoothly.
“A tool should never create stress at the moment you use it.”
That idea is built into this mechanism.
The Reassurance of Always Having It With You
THE CARD BAG is a small product.
But we believe it can bring a meaningful change to everyday life.
Light enough to carry without burden.
Simple enough to make you want to take it out and use it.
A reusable bag that feels good every time you use it.
No more rushing at the checkout counter.
No more trouble with unexpected shopping.
THE CARD BAG is made to support those everyday moments.
Trademark application pending / Utility model application pending(No. 2026-1866)
Developed by MONDO DESIGN CO., LTD.
MONDO DESIGN CO., LTD. is a bag manufacturer that has been developing SEAL, an upcycled brand made from discarded tire tubes, since 2007.
Our philosophy is to give new value to materials that were once destined to be thrown away.
Guided by this belief, we continue to create carefully made products through Japanese craftsmanship.
SEAL uses discarded inner tubes from large truck tires.
Because the material is water-resistant and highly elastic, we found it to be well suited for bags and mobile accessories.
Since then, we have continued to research and test not only discarded tire tubes, but also many other resources that were previously thrown away after use.
By bringing out the unique qualities of each material, we transform them into new products with renewed value.
We also work on product development using materials that have been discarded after events, exhibitions, concerts, construction projects, and other temporary uses.
Each waste material has its own background and story.
Our goal is to preserve that story while turning it into a new product with real value.
To create high-quality products at fair prices.
That is the foundation of our manufacturing.
THE CARD BAG carries that same DNA.
A small choice not to rely on disposable bags.
We created this bag because we believe that many small choices can eventually lead to meaningful change.
