By OLIVER STRAND

Every so often, a tool will leap across professional borders and become standard in restaurant kitchens. The blowtorch caramelizes as well as it solders. Today, the woodworker¡¯s Microplane rasp is far more likely to zest a lemon than shape a credenza.

The most recent cross-disciplinary tool in a chef¡¯s batterie de cuisine comes from the operating room: medical tweezers. They allow a chef to put the final, seemingly impossible touches on a dish.

¡°I was using tweezers to handle a thin stream of strawberry puree frozen with liquid nitrogen because if you touch it, it falls apart,¡± said Grant Achatz, the chef at Alinea in Chicago. ¡°Tweezers allow boundary-pushing with scale and texture.¡±

Tweezers are altering how chefs move in the kitchen . Surgeons use medical tweezers, which have delicate, thin tips, for suturing, cauterizing or removing debris. Chefs favor them because they are more gentle than tweezers designed for plucking eyebrows or extracting pin bones from a fish. An offset tip is less likely to bruise a blossom clipped from a flowering herb. And chefs favor tweezers over fingers as well as tongs, which are banned in some restaurant kitchens (too clumsy).

Chefs say tweezers started to appear in European restaurants in the mid-1990s. They were the Western answer to kitchen chopsticks . Tim Mussig, the purchasing director for the professional kitchen supply company J. B. Prince in the United States, said sales of tweezers had been growing steadily since the store introduced them in November 2008.

¡°As the food becomes more precise, there¡¯s a lot of handling involved,¡± said Daniel Humm, the chef at Eleven Madison Park in Manhattan. ¡°There might be 10 things on a dish, but tweezers keep your hands clean and you keep the plate clean.¡± Just as important, they make all that work appear effortless.

The nasturtiums scattered stamen- side up, or the microherbs balanced on the tips of steamed vegetables, or the paper-thin slices of vegetables draped over cured Japanese beef? They were all placed there with tweezers.

¡°It¡¯s harder to make it look like you didn¡¯t try,¡± said the chef David Chang, whose kitchen crew at Momofuku Ko tweezes extensively. ¡°It¡¯s more difficult to make it seem it¡¯s plated as it falls. It¡¯s not rustic. It¡¯s naturalistic. It sounds stupid, but you¡¯re using tweezers to make it seem natural.¡±