This is my favorite GE lamp etch. When were these etches used?

Loved these old GEs. The exact etch you see here was used from about 1951 to 1959. A slightly smaller, outside marked version of this style was used between 1959 and 1979 on 40w-100w A-19 bulbs. There's some overlap, depending on the bulb type and the factory, for example some inside etch GE incandescent bulbs were made into the early 60s and some of the 60s-70s etches made it into the early 90s on certain types.