A California startup called Advanced Life Technologies (ALT) LLC has made it their mission to not only provide a range of 3D printing services, but to do it sustainably - and help others to make sustainable choices as well. ALT LLC emphasizes the use of sustainable materials, and recently they developed their processing technology to turn plastic waste, such as bottles and packaging material, into PLA, PP, PET and other recycled filaments. They also offer ABS made from recycled automobile components. While their recycled filament isn't on the market, they offer it gladly as a material option for requested prints. Read more at 3DPrint.com: https://3dprint.com/154467/alt-llc-recycled-filament/