How do I? Is it possible?

[azure_]

Is it possible to make a white crested black polish with golden lacing on his/her back? If so how could I make it?

 

[casportpony]

You should ask this in your other thread too.
https://www.backyardchickens.com/threads/what-would-happen.1402795/

 

[nicalandia]

Is it possible to make a white crested black polish with golden lacing on his/her back? If so how could I make it?

Not possible because White Crested Blacks are based on Extended Black, Silver/Golden Laced Polish are Birchen based with a host of other genes to produce the lacing(Db,Pg,Ml,Co)

 

[azure_]

Ok