NinjaFlex filament

See the following -

Obliterate the Cost of Consumer Products with Open Hardware

If you're looking for free and open source designs to replicate on your desktop 3D printer, you have about two million choices. Because the open source ethic is rooted so deeply in the 3D printing community, many of the consumer products you would normally buy are already among those millions of predesigned products. You can download the designs and save a lot of money. My group has shown in studies in both 2013 (on a self-built 3D printer) and 2017 (on an out-of-the box 3D printer) that peer-to-peer sharing prosumers (producing consumers) gain an incredible return on investment: > 100% at minimum and more likely ~1000% by 3D printing products to offset purchases only once a week...