While watching a video of a man feeding his guinea pigs with homegrown grass, I realized that grass roots take on the shape of whatever container they're placed in. Inspired, I 3D designed a mold of my favorite slides and grew wheat grass in them to make Grass Shoes.
The roots followed the layer lines of the 3D mold
3D model of Shoe Mold
I left the shape of the mold under the strap intentionally blank since it needed to be made of a bendable material or it would break the roots. I didn't have access to a 3D printer that could successfully print flexible material so I substituted polypropylene. Due to its sturdy yet pliant nature, it allowed the successful removal of that part of the mold.