This material is derived from the recycling of plastic bottles. PET generates less ecological impact during its production than polyester*: its production requires 59% less energy, and generates 32% less CO2 (according to the Swiss Federal Office for the Environment).
However, it is not a sustainable solution because closed-loop recycling of polyester does not exist, polyester recycling is energy intensive and requires the use of chemicals, it releases microplastics during washing which end up in our oceans.
* banned material on KAP