Great question! At EXALT we take both sustainability and your personal preferences very seriously.We can offer insulation made from denim offcuts rather than wool if you would prefer. If you'd prefer denim insulation please be sure to add this to your order notes at checkout.Denim is a great insulator, it's sustainable, and it's a clever way to give a second life to material that would have otherwise gone to waste.However, occasionally we might need to use an alternative. In such cases, we use wool insulation. But don't worry, it's not just any wool. This is cruelty-free, fair-trade wool that would have otherwise been discarded. By using this wool, we can contribute even more to sustainability than if we used common alternatives like polystyrene (even if they are much cheaper)Regardless of which insulation we use, please rest assured that the products inside your order are always 100% vegan.We're committed to improving and refining our processes, and we greatly appreciate your understanding and support. If you have any other questions, feel free to reach out to us! Check out some other great ways to reuse your packaging.