When you are working with sportswear, outerwear or swimwear, synthetic polymers are your best friend. Because they are not biodegradable and they require permanent non-restorative extraction, they are considered non-renewable resources. But if you reuse the same material over and over again, than the biodegradability factor matters no more and the need for extraction disappears completely. One important condition for this to work is that the fabric should be a mono-material (100% polyester, 100% nylon etc.) so that it could be recycled and used for a new garment. Fibers such as @BionicYarn or #Econyl are a great substitute for virgin polyester and nylon. They are mechanically regenerated yarns that can be reused further on, indefinitely. You just have to think how you can bring the garments back to you when they reach the end of their life, so that you can reuse the fiber within them.
As for natural leather, looking at the bigger picture, the more we as designers demand it, the more we encourage factory farms and slaughterhouses to increase their production. But if you love working with leather and you don’t want to give it up than maybe you will consider doing it in a responsible way. When it comes to leather goods, sustainability is challenged because of the concerns regarding ethical and animal welfare problems; and I couldn’t agree more. In an ideal world we would not consume animals but rather just coexist with them. But that falls into the “utopia” category so we have to be realistic, adaptable and practical. That is why, what we can do is asses our supply chain and trace where the leather is coming from and how the farmers care for the animals. We are lead to believe that a big percentage of the leather used in the lifestyle industry comes as a by-product of the meat industry. However, more often than not, the leather is a subsidiary or a primary reason for value. Therefore, exotic leathers are out of the question! They will never be a by-product so don’t kid yourself. The upside is that when the leather is truly a by-product, than by using it we are preventing waste. Chicken skin or fish skin, for example, are really cool-looking and resilient materials. So get creative and use what we would normally throw away, you can’t get more innovative and sustainable than that.