Patina is generally considered as a darkened or toned surface layer that gets created on an item over a long period of time, sometimes over decades or even centuries. One of the biggest reasons why so much importance is given to patina is because it is seen as the primary indicator of the genuineness of an item. Due to this, it is vital that you select the right person for the restoration or
conservation
work to ensure that it doesn't get destroyed in the process.