I too have noticed; there appears to be a very light color stock variant, I’ve been calling them white backs vs. cream in my notes. The very light backs are much tougher than the normal cream. I’m not sure if it runs through every series (I still am not sure what the series even are, I suspect 5 series of 32 but nobody seems positive or has brought direct evidence), I will have to go through my set. I do not believe it to be toning but am happy to be shown wrong.
Bowman used different stocks in 1952 1-72 as well, and of course the 1949 1-3, 5-73 series’.
|