Newsprint in the 60s & 70s

[James44]

I very much appreciate the answers I got on my previous question about print blankets.

I have another question that perhaps someone here may know, or know where to look:
Does newsprint have a watermark on it?
Did it have a watermark on it in the late 60s and 70s?
If so, what would it be, a letter, or some mark?

Thanks in advance for any assistance.