The term tin plate has been defined. Terne plate is a plate of sheet iron coated with tin and lead, and is inferior in quality to tin plate. Plates in the market are known as charcoal and coke plates. These terms, derived from the process of making the iron, are used to designate the grade of plates, when marking the boxes containing the goods.

Brands are the different marks or devices used by makers. Reliable manufacturers always endeavor to maintain a uniform grade of merit in the different brands they turn out Gauge denotes the thickness of the plates, and is known by such signs and marks as I C, I X, etc. I C represents a plate in gauge about No. 29, and weighing about 10 ounces to the square foot. I X corresponds to No. 27 gauge, and weighs nearly 12 ounces to the square foot.

Sizes of the plates are marked on the boxes. The common sizes are: 10 in.xl4 in., 14 in.x20 in., 20 in.x28 in., etc.

Waster is an imperfect plate.