gistfile1.swift

// Extend UILabel with a method which sets font, to be used by UIAppearance
extension UILabel
{
    func setFontName(fontName:String)
    {
        self.font = UIFont(name: fontName, size: self.font.pointSize)
    }
}

// Somewhere in the code, call the extension method on the UIAppearance proxy object of UILabel, example:
//
// UILabel.appearance().setFontName("HandelGothicBT-Regular")
//