Plate
Plate turns up in 2 fields: printing, shop slang. Here is what it means to the people in each one.
Plate in printing
A flat, flexible sheet of metal or polymer that carries the image to be printed.
A thin, flexible sheet mounted onto a press cylinder to transfer ink to paper or to an intermediate rubber blanket. In offset printing, plates are usually made of aluminum and chemically treated so only the image areas accept ink. In flexography, they are made of photopolymer rubber with raised image areas.
"Hang the cyan plate first and let's check the registration before we mount the rest of the colors."
Plate in shop slang
A flat piece of metal that is significantly thicker than sheet metal.
A heavy, flat piece of rolled metal, typically steel or aluminum, used in heavy fabrication and structural construction. In industrial standards, flat metal crosses the threshold from sheet to plate when it exceeds a certain thickness, usually around a quarter of an inch or six millimeters. It requires heavy machinery to cut, bend, and weld.
"The forklift chassis needs a half-inch steel plate welded to the bottom for extra counterweight."