Q.Type-4 is a 40-liter backpack, what did you think was important in developing it?

When the backpack grows in size, the frame is inserted to maintain its shape, and the weight increases.
It is also important to reduce weight by using functional fabrics to produce lightweight backpacks.
I thought it was difficult to reduce the weight of the backpack fundamentally as long as there was a frame.
I started the development with the idea of making the back plate stable without a frame.

Q.What was the most difficult thing about developing a new backpack? 

Without solid support like a Aluminum frame, it seems that it was more difficult to make the backboard in a curved shape than expected.

Of course, there was a plastic-like form in the mound, but that alone made it difficult to maintain a curved shape.

After several trials and errors, we were able to succeed in producing in a way that was completely opposite to what we had originally thought.

Q.What design elements did you focus on? 

I wanted to keep the diagonal zipper of the existing type-1 backpack. 

because I thought that the role of diagonal zipper would be bigger if the backpack size was bigger.
Because of the zipper, there was an inevitable shortage of the front top space, which was solved with a detachable multi-pack.
The multi-pack was produced by removing the inner foam from the existing lens pack and changing the design to fit the backpack.