The best part of the fold-in was the comically cynical idea behind it that collectors of Mad Magazine had to ruin their issue to do the fold-in thus forcing them to buy another issue to keep in “mint condition”. Was a meta-satire on the collecting hobby that required collectors to not actually use and enjoy the collectible.
Not really- my friends and I would just sort of bend the pages gently and you could see the combined picture just fine, and always flattened back out no problem if stored in a plastic insert with cardboard backing.
Most people I knew didn't fold them completely ever, and we were just kids.
I'd have to imagine it was the same for the collectors.
Boy, I sure did. I found getting the fold absolutely perfect a bit of an obsessive compulsive experience that ultimately paid off big time once I nailed it.
The drawings and supporting copy were almost always jaw-dropping genius that blew my mind. The kind of thing I'd always want to share with someone else in the house once I'd done the fold.