Russia iron is used for roasting pans, baking pans, and also for stove pipes,
patent elbows, etc. It is a special grade of sheet iron with a glossy black,
slightly mottled appearance, due to oxide adhering to the surface so tenaciously
that it cannot be cracked off by repeated bendings. It is produced by passing
a pack of heated sheets back and forth under a steam hammer, the bit and anvil
of which have indentations on their surfaces. Sometimes charcoal powder is sifted
between the sheets before heating. In the trade it is known as "planished iron".