In one sentence, describe what the following article is about:

Some backpacks state that you cannot fully submerge them as colours may bleed or material may be damaged. If you cannot fully submerge your backpack, use a wet cloth or sponge together with cleaner. Dry your backpack upside down away from any direct heat sources. Do not place your backpack in the dryer as it may damage the material. Make sure that your backpack is completely dry before putting it away as mould can grow on moist material.

Summary:
Follow the care instructions if you should submerge your backpack. Dry your backpack.