In the quest to carry along all we need while backpacking, even as we keep the load as light as possible, someone came up with the idea of an internal frame backpack. This is a large backpack that does not include any type of outside framework, but relies on a very basic and lightweight interior frame to keep the shape intact, while also providing adequate room for all backpacking essentials. Often, backpacks of this nature have frames that are made of light but resilient plastic, or a lightweight metal such as aluminum. The sections that make up the frame will often be flexible enough to mold to the contours of the wearer’s back, which makes the backpack easier to shoulder for long distances.
In addition to the light frame segments, the interior of the internal frame backpack is usually reinforced with a series of cloth strips that act as an interconnecting network within the pack itself. These straps help to support the frame in maintaining the structure of the backpack, and also make it easier to pack the unit for an even distribution of weight.
Unlike backpacks with an external frame, there is nothing on the outside of an internal frame backpack to allow for the addition of other items by means of clipping on to rings and other devices on the outside of the pack. All materials that the carrier wants to take along will need to be secured within the bag itself. If the backpack is prepared properly, there will not be anything moving about during the hike, so the weight distribution should remain constant.
The internal frame backpack is an ideal choice for a long hike or for backpacking through terrain where there may be branches and undergrowth that could snag on an external style pack, or something that is connected to the pack. Because everything is safely tucked away within the bag, nothing can snag or be exposed to the elements as the person travels. The result is that all the contents of the backpack are as fresh and ready to use as when they were placed into the bag. This particular attribute is one reason that the internal frame backpack has surpassed the older backpack types in popularity, and will probably continue to become more popular in the years to come.