 Neon tube lighting, which also includes the use of argon and mercury vapor as alternative gases, came to be used primarily for eye-catching signs and advertisements.Neon lighting was relevant to the development of fluorescent lighting, however, as Claude's improved electrode (patented in 1915) overcame "sputtering", a major source of electrode degradation.Sputtering occurred when ionized particles struck an electrode and tore off bits of metal.