Internal frame backpacks have a lightweight frame made of plastic or aluminum, with fabric straps for support. They lack external attachments but are ideal for long hikes and rough terrain, keeping contents safe and fresh.
In an effort to carry everything we need while backpacking, even if 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 kind of external structure, but relies on a very simple and light internal frame to keep the shape intact while providing adequate space for all the essentials of the backpack. Often, backpacks of this nature have frames made from lightweight but strong plastic or a lightweight metal such as aluminum. The sections that make up the frame will often be flexible enough to conform to the contours of the wearer’s back, which makes the pack easier to carry over long distances.
In addition to the lightweight frame segments, the interior of the internal frame backpack is usually reinforced with a series of fabric strips that act as an interconnecting mesh within the backpack itself. These straps help support the frame in maintaining the structure of the backpack and also make it easier to pack the unit for even weight distribution.
Unlike external frame backpacks, there is nothing on the outside of an internal frame backpack to allow for the addition of other items by attaching rings and other devices to the exterior of the backpack. All the materials that the courier wants to bring with him must be secured inside the bag itself. If the pack is properly packed, there won’t be anything moving during the hike, so the weight distribution should remain constant.
The internal frame backpack is an ideal choice for a long hike or backpacking through terrain where there may be branches and undergrowth that could snag on an external style backpack or something that is attached to the backpack. Since everything is safely hidden inside the bag, nothing can get caught or 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 in the bag. This particular attribute is one of the reasons why the internal frame backpack has surpassed older backpack types in popularity and will likely continue to become more popular for years to come.