Bella Hadid’s “spray-on” dress was not a real dress, but rather a clever optical illusion created by the designer, Dutch fashion designer Iris van Herpen, using 3D printing technology. The dress was created by printing a transparent polymer material onto Bella Hadid’s body, giving the illusion that she was wearing a dress that had been spray-painted onto her skin. The dress was showcased at the Paris Fashion Week in 2019, and it quickly went viral on social media due to its unique and innovative design.