Yokohama Canvas Bags with shoulder straps have D-rings that fasten the leather parts with round rivets. A high-density nylon woven tape is inserted inside to prevent the leather parts from stretching. As long as the metal rivets are not damaged, it's fine, but if you swing the bag around by holding the shoulder strap or take it off roughly, gravity will be added to the weight of the bag and cause stress.
For example, if the weight of the bag (including the contents) is about 3kg, and you drop it from your shoulder to the ground, gravity (weight x 9.8) will apply a load of about 30kg to the D-ring fasteners at the joint of the shoulder belt for an instant. Since the shoulder belt is joined at two points, each D-ring fastener will be pulled by a force of 15kg. The bag weighs 3kg including the contents, and you are not carrying anything that heavy, but it broke. You will be left lamenting that.
Please also be aware that the seams where the bag is sewn together are also subjected to similar stress.
Therefore, Yokohama Canvas Bags are made from a single piece of fabric and are not sewn together at the bottom. If the bag was made from two pieces of fabric and sewn together at the bottom, the weight x gravity would be applied to the seams, which could cause the threads to break and the bag to puncture. Yokohama Canvas Bags are fine as long as the fabric is not torn.

The same goes for handles of tote bags, etc. When lowering a tote bag that you are carrying on your shoulder to the floor or a bench, drop it from your shoulder without waiting for the handle and grab the handle. In this case, the load of weight x gravity is applied to the connection between the handle and the main body (sewing thread, rivets, etc.) just like in the case of shoulder belts, so please do not handle it in this way.
After all, we want you to treat your bag with the same kindness you would treat your partner.
That is the secret to its longevity.

Yokohama Canvas Bags has products with zippers, and AKB (Aviator's Kit Bag) products in particular have a double zipper with two sliders that allow you to open and close it freely at any point. There is no problem if you place the bag on a table or bench and open and close the zipper, but when you are carrying the bag across your shoulder and try to pull the zipper slider to open and close it, you will inevitably pull the slider toward the selvedge (the part of the fabric where the zipper selvedge is attached) on either the left or right side of the line, even though you should move the slider along the line of the zipper selvedge (the metal part that locks the zipper). If you do this, the metal part of the slider will rub against the zipper selvedge, and if this is done repeatedly in the same place, the selvedge will tear, or the selvedge will tear and the selvedge will come off, making it impossible to open or close the zipper.
Each person has their own way of using things, so just like with shoulder straps or handles, if you treat it roughly, it will break.
The zippers used in Yokohama Canvas Bags products are the world-famous YKK zippers. We use them because we believe they are the best quality product for zipper parts.
I hope that people will once again be considerate of their bags, which have become their partners, and think carefully about how they will use and handle them.

This is a Yokohama canvas bag product that comes with a shoulder strap so you can carry it over your shoulder or across your shoulder. It is a model with a handle, such as the AKB (Aviator's Kit Bag) M18B1, M17B2, M19A2, and M17A3.
Many people carry their bag with the handle part sandwiched between their body and the bag when it is sashed. If the handle tape (most Yokohama Canvas Bags use high-density woven acrylic tape) is sandwiched between the body and the bag, it will rub and wear down, causing the woven threads of the handle tape to break or fray.
Therefore, when carrying the bag over your shoulder, be careful to carry the handle part (the part you grip) so that it is not pinched between your body and the bag, but is folded down on the side of the opening of the bag.

革ハンドルなど革の部位によって硬さや革裏面の表情が異なり毛羽立ちがあるモノなどバラツキがありますが、ご了承願います。

また、横濱帆布鞄では牛革のハンドルなど部分的に使用していますが、色染（特に黒色）している革ですので、雨に濡れたり汗などで革色が衣類などに移染したりしますので、ご使用には十分ご注意ください。

市販の防水性スプレーは、防水性帆布鞄には必要ありませんが、綿・ポリエステル帆布素材に合ったものをご使用ください。また、防水性スプレーは、革ハンドルやパーツ、スタンプマーキングの顔料を溶かしてしまう場合がありますので、ご使用には十分ご注意ください。