Very old, 50s vintage. May not even have come out of a Soft-White package, rather called a Deluxe White lamp. The term "soft white" was coined for white incandescent bulbs in '59.
Do you mean the type of etch? The etch on this lamp is hard to read because ink isn't even used. It's just a clear outline in the soft white finish. All early GE q-coat white lamps had this.
So, this one has inside white coated (Some form of Silica crystal coating) instead of inside etch frosted bulb (The one that used acid etch for frosted appearance).
The GE Q-coat lamp is an inside frosted bulb with an additional thin layer of silica. In the early 80s GE went to fully silica coated bulbs without the inside frosted glass because it was cheaper.
The original Westinghouse and Sylvania soft white bulbs also had a similar finish, but were phased out by '59 or '60. However Westinghouse did make a few of the older soft white bulbs until the early 80s, and even seen a few Philips ones.
I have 4 working Q-coat lamps in the 25W version. I used to have 5, but one burnt out on me several months ago. At least it did more than 500 hrs, mostly to keep some light in my bedroom.
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At least it did more than 500 hrs, mostly to keep some light in my bedroom.