Hi Hancock 52,
Sorry if I was a bit vague, but I was referring to the drumhead tail sign City of San Francisco. It appears to be a photo negative of some sort.
Thanks, Teddymich
I think what he did was copy a web graphic of the tail sign - assuming that we talking about the roughly inverted T-shaped one. If I am not mistaken the graphic is reproduced somewhere in that thread.
You can print things like this on inkjet transparent film or on semi-opaque paper and light them from behind. I think that part of the advice was to print a second sheet to go behind the print with everything but the lettering blacked out. That way you get the background light mostly visible in the lettering.
I am doing roughly the same thing. I've started with an image of a neon sign which I am going to put in an old K-Line square tail sign mount:
As far as I know this is not prototypical but I am working my way up to something more complicated.
Postscript: I don't see the graphic I was thinking of in that thread but this is what I was thinking of:
Also, I see that T. Albers got further than I did in researching the square sign although I believe it's for a different train: