There is no idiom starting with the word "plastic".
Idioms containing the word "sculpture":
Wood carving and clay sculpture: ?The pronunciation is mù diāo ní sù. Definition: An idol carved from wood or shaped from clay. Describes a person who is dull and inflexible or has a sluggish expression. Source: Chapter 27 of "Dream of Red Mansions" by Cao Xueqin, Qing Dynasty: "The Daiyu leaned on the railing of the bed, holding her knees with both hands, with tears in her eyes, like a wood carving and clay sculpture." Grammar: conjunction; used as attributive and object.
Clay wood carving: ?The pronunciation is ní sù mù diāo. Definition: Refers to idols made of clay or carved from wood. It is a metaphor for people's expressions and actions being dull. Source: "The Surprise at the First Carving" Volume 30: "Li Canjun spent his days in vain on many romantic and charming things, talking and laughing, but he didn't know where he was in Java. Compared with the clay sculptures and wood carvings, they were so trembling." "Lao Can's Travels" Chapter 7 of "Episode 2": "The strangest thing is that there are so many men and women behind the birthing station, all of them look like clay sculptures and wood carvings. No one speaks or smiles, and no one looks around." Used as object and attributive; to describe people's movements and expressions.