A bag made with real full-grain leather like the ISM backpack is made to last for years, especially if it's regularly taken care of. To make sure your leather bag lasts for the duration of its use, this is one method for cleaning and ensuring your leather bag’s longevity:
1. Remove dirt and dust
Use a shine cloth, brush, or damp towel to wipe down any dirt and dust that appears on your backpack. This works for the leather parts of your bag as well as the nylon portion. Over time, you might notice white marks appear on the nylon from pressure points and these can be easily removed with a slightly wet towel.
2. Apply a leather cleaner
If your bag has small scratches, applying a leather cleaner can help remove some of the visible marks. Add a small amount of leather cleaner to the surface of the leather and using a shine cloth or soft towel, use circular motions to cover the affected areas.
3. Use a leather conditioner
Adding a layer of leather conditioner on top of a cleaner can help condition the bag by keeping the leather membranes soft. Similar to how you'd apply a leather cleaner, use a shine cloth or soft towel to rub the conditioner across the leather surface.