Bronzing is a process by which a bronze

Bronze

Bronze is a metal alloy consisting primarily of copper, usually with tin as the main additive. It is hard and brittle, and it was particularly significant in antiquity, so much so that the Bronze Age was named after the metal...

-like surface is applied to other materials (metallic or non-metallic). Some bronzing processes are merely simulated finishes (patina

Patina

Patina is a tarnish that forms on the surface of bronze and similar metals ; a sheen on wooden furniture produced by age, wear, and polishing; or any such acquired change of a surface through age and exposure...

s) applied to existing metal

Metal

A metal , is an element, compound, or alloy that is a good conductor of both electricity and heat. Metals are usually malleable and shiny, that is they reflect most of incident light...

 surfaces, or coatings of powdered metal that give the appearance of a solid metal surface. In other cases, an actual layer of heavy copper is electroplated

Electroplating

Electroplating is a plating process in which metal ions in a solution are moved by an electric field to coat an electrode. The process uses electrical current to reduce cations of a desired material from a solution and coat a conductive object with a thin layer of the material, such as a metal...

 onto an object to produce a bronze-like surface. This electroplating

Electroplating

Electroplating is a plating process in which metal ions in a solution are moved by an electric field to coat an electrode. The process uses electrical current to reduce cations of a desired material from a solution and coat a conductive object with a thin layer of the material, such as a metal...

is the method traditionally used for "bronzing" of baby shoes. But to electroplate a non-conductive item like a baby shoe, a conductive material must first be applied. Then the copper plating is done.