Take a look at your box of delivery sushi. Notice that little green plastic rectangle separating your fish from your wasabi and ginger? You know, the one with the fringes on the top that looks like a two-dimensional sliver of astroturf? Well, in the sushi days of yore, before takeout boxes and plastics were a thing, that divider served a more functional purpose of wrapping and protecting balls of fish-topped rice. And it was made of real leaves, often from bamboo. And sometimes it was carved into stunning works of art.

Sasagiri is the centuries-old Japanese craft of carving intricate designs into bamboo leaves. Because of the time and skill involved, few modern sushi chefs practice it. Masaki Saito of Sushi Ginza Onodera in New York is one of them. The sushi master began learning sasagiri when he was just 18, and at Onodera, he uses intricate designs like this butterfly to line to-go containers.

See how he does it in the video above, and get a peek at a traditional craft well worth preserving.