Question about '70s rack packs
 

I have been picking up mostly graded wax and cello packs from the '70s. However, a good bit of my childhood collection came from rack packs and I look at them on eBay and may at some point purchase some.

My question is in regards to the plastic the packs are made out of. My personal recollection is that the plastic was of the stiffer variety, and even looks to have yellowed over time, but not very flimsy looking at all. I see packs that appear very much as I remember them, but I also see packs where the plastic looks 'clearer' and just to my eye looks like a different plastic, specifically some '79 packs I have seen. Does anyone have any knowledge of what is the appropriate packaging, or did it vary through the '70s and my memory is just showing the effects of that being 38+ years ago?

Thanks for any thoughts you might have.

my memory
 

Well, I don't do anything with unopened material today, but I was buying packs actively from 1975-1981. My recollection of the racks is similar to what your recollection is. The rack packs were in some pretty heavy duty plastic - used to use my teeth to get it started. Cello's were a much thinner plastic......as best I recollect!

Thanks for the response. So, maybe I'm not too foggy since you seem to remember the same thing. Yeah, cellos were always a thinner, typical cello type material to the best of my memory and recent experience.

On the same topic, sort of, it bugs me that people sell lots of the header cards from the rack packs. So, why would someone need 25 header cards? Hmmm.