Superimposed titles early 1960s

[garygraham]

I'm intrigued by these superimposed titles on "The French Chef" a programme from the early 1960s made by WGBH Boston. They look more three dimensional than I would expect on a programme from this era when the only methods in black and white TV seemed to be either luma key or a straight mix. Any thoughts? 

[sonnybh]

Usually the captions in the era were foil printed onto black card, I have a book on TV graphics which mentions this was a standard method.