Real materials 6:
This tessellation in plaster is the work of R. S. Newall, an engineer and artist from New Zealand.
To make this piece, he first carved a prototype of a single duck in wax.
He then placed the wax version flat-side-down in a pan, and poured plaster on top to create a mold.
Next, he removed the wax duck, lined the mold with plastic food wrap, and poured plaster-of-paris into the mold.
Next, he placed a sheet of piece of plastic food wrap on top of the whole thing, turned it all upside-down (!) onto a flat surface, and pressed downward to ensure that the back of the new plaster duck was perfectly flat.
Last, after carefully removing the new plaster duck from the mold, he repeated the process eight times and painted the group.
Mr. Newall's inspiration for 'Devil Ducks' can be seen here, here, and here.