Rectangle

They offer high thermal performance thanks to their narrow design, which reduces air gaps and heat loss. They are lighter than rectangular ones due to the use of less material. Recommended for hiking, mountaineering, or extreme temperatures.

It plays an important role, depending on the intended use of the sleeping bag. Ideally, for hiking, trekking, or mountaineering, a sleeping bag weighing less than 1.5 kg is recommended to facilitate transport and reduce the load on the backpack.

On the other hand, sleeping bags with greater weight are preferred for camping or stationary use.

Left

It not only concerns the ability to connect with another sleeping bag but also the ease of use. The zipper on the left side (as you lie down) is more convenient for right-handed people.

Hollow Fiber

Type of synthetic filling that offers better insulation than other synthetics (due to hollow fibers that trap air) and retains warmth even when wet. It is economical and easy to care for. However, it is heavier and bulkier than down and loses its effectiveness over time.

The warmth of a sleeping bag is determined by the fill density inside it, which is measured in grams per square meter (GSM).

1000

Suitable for very low temperatures.

Polyester

Durable and economical synthetic fabric, ideal for the exterior or interior of a sleeping bag. It does not absorb water, so it dries quickly and withstands moisture, while being resistant to sunlight and daily use. Its main disadvantage is that it may not be as soft to the touch as other fabrics.