Why are people with surname Smith called Smudger?

People with the surname Smith are often referred to as "Smudger" as a playful nickname, stemming from the association of the name Smith with blacksmiths or those who work with metal, leading to the idea of them being dirty or "smudged" from soot and grime. The term is largely informal and can be used affectionately or humorously. Additionally, it reflects a camaraderie among those sharing the common surname.