Tin is the traditional lining for copper pots. Tin bonds chemically with copper—it's very malleable and melts easily, so it melds beautifully into the lining of a copper pot.
We use a double layer of 100% pure tin to cover the interior surface of our cookware.
Tin also makes a good lining because it doesn’t react to acid and is relatively nonstick. Unfortunately, it has a low melting point of 450°F, so it can wear through.
In USA there are also few workshops who can offer this service.
If you have ever burnt your beloved cookware badly or scratched it up by accident, if this were a copper pan with a tin lining you can have it re-tinned at a fraction of the cost for a new pan.
If your stainless steel lined copper pot is scratched or ruined you have to get rid of it altogether and buy a new one- hopefully this one will have a tin lining.
In France or Italy, restaurants regularly send out their pots and pans to be re-tinned.