One clever idea is to use them as a mold to make beautiful cement planters. You can use the box as is to create a planter ...

Placed right side up, they make for a fun mold. Once the cement itself has ... post-craft -- it's easy enough to transform plastic pots into cement planters as a DIY, too, so you can create ...

[Thomas Sanladerer] wanted to create some molds using 3D printing for concrete and plaster. He used a delta printer with flexible filament and documented his process in the video below. If you ...