Insulation

If you tie the item with a wire and put it in the plating solution while passing the current on the-side, the current will flow.

If this wire is tied with silk thread, no current will flow.

Also, as for the wire material, the current flow is better with copper wire or brass wire than with iron wire. A conductor in which an electric current easily flows is called a "conductor". A material such as silk thread that does not allow current to flow easily is called a "non-conductor".

Even when the items are connected by a conductor, the current does not increase to infinity, because it has the property of blocking the flow of current through the conductor.

This is called "conductor resistance", and ohm (Ω) is used as the unit of resistance.