I really enjoy this part of the sculpture process. It is the icing on the cake after many many hours of work, and once the bronze sculpture gets that patina all that remains is installation or mounting. Below are a few pictures of the maquette (1/4 life size standing 18" tall) getting a traditional patina (consisting of blacks & browns). A patina takes the bronze piece which is a gold color, and changes the color by use of chemicals that are applied when the piece is cold or hot. If the piece does not get a patina it will change colors by exposure to the outdoors and air similar to copper.
The pieces are getting spun on a sculpture stand as he (Mike at the Bronze Works Foundry) takes a torch working on heat consistency throughout the whole piece. It can be really difficult to get the arms of the child to remain at the same temperature as the robe. Once it has reached the right temperature the pieces are sprayed with ferrous sulfate. I comment on what places I think need more or less color. I particularly like rubbing the spots that I want to stand out with a skotchbrite pad like the child's feet. Certain areas tend to get too dark so it is really important to pay attention to every area. If something gets missed and it can't be fixed then the piece has to get sandblasted and started over with.