Three of the packs we reviewed use bio-based Dyneema in their construction. Dyneema is an ultra-high molecular weight polyethylene (UHMWPE) fabric, which is incredibly strong but also very light. Bio-based Dyneema is made from the by-product of the pulp and timber industry and has a carbon footprint that is 90% lower than conventional UHMWPE fabric. Despite seeing packs from multiple brands using bio-based Dyneema, we opted to give those specific backpacks a soft rating bump rather than creating a bio-based product category. This is because bio-based Dyneema is primarily a replacement for the UHMWPE nylon used in ultralight packs, which is not applicable to all the backpacking packs we reviewed. Additionally, the use of bio-based materials in packs was not prevalent enough to justify creating a separate sustainability criterion.

Another category we briefly considered was the use of undyed fabric in packs. This came to our attention because Granite Gear offers an undyed option for their Crown3 60 pack. According to Granite Gear’s site, the undyed option reduces water consumption by 55%. Furthermore, synthetic dyes can be harmful due to the release of chemicals into the environment. While we applaud Granite Gear for offering an undyed pack, this practice would need to be more widespread to warrant its own category. Similarly, we considered including solution-dyed fabrics, which offer reduced energy consumption, water use, and greenhouse gas emissions in comparison to traditionally dyed fabrics. Unfortunately, while synthetic backpack fabrics could be solution-dyed, the practice was not common enough to include in the backpacking pack category.