Backpack weight and size are always an issue when travelling, whether that be weight restrictions on flights or the amount of weight you can physically carry comfortably. A lot of the time the kit you want to take with you will have to be a miniature version or removed from your pack altogether. If you think you are going to need extra luggage space when travelling i.e. for souvenirs, then it is always a good idea to take a lightweight packable rucksack or duffle bag with you. The lightweight daysacks are especially useful as they can be used for sightseeing trips whilst you leave your main backpack in your hotel room.