I stumbled across something that was both interesting and infuriating a couple of weeks ago concerning a 1952 Topps Baseball pack opening. Yes, certainly an interesting thing to do but it's infuriating to me that it survived 70 years and then got dismantled. Here's a link to the whole video but you will need to watch it on Cardporn's Facebook feed (sorry).
However, there's a silver lining, or at least a white one. I've known for some time that many of the early penny and nickel packs sold by Topps came with a glassine insert that I thought helped protect the cards from the gum. However, it seems, after watching the video, it's possible the insert was fashioned in order to allow the gum to be inserted into the pack to allow for a neat final sealing job vs. being a purely protective measure.
Here, check out these two frame grabs to see what I mean. This is the arrangement after the pack was opened; you can see how the white insert is partially, but neatly, folded around the five cards within: