Part of my job is to write and produce documentaries - as a result, I look at a lot of old home photographs. I've noticed something strange - the color prints made in the 70s and 80s are awful - the color is faded and deteriorated - not to mention that awful satin finish. I expected to see that.

But the photos made in the late 50s and early 60s still look good - a little yellow sometimes, but easily color corrected. They were probably made from 120 or 620 negatives as they are square. What was changed about processing/paper in the late 60s/early 70s?
juan