Depression Era Saving Taken Too Far

I've been shredding my mother-in-law's decade and older documents, and have come across all sorts of things she had used to save a penny or two. Mainly, she's taken used envelopes and recycled them to store other documents, by adding her own handwritten note of their contents. Some of these envelopes two or three handwritten notes as to their contents. Not too bad, and definitely a money saving technique. I've always been a little in awe of how much my mother-in-law's been able to save over the years, and recycling old envelopes is definitely good for the environment. But today, I came across a stack of old Christmas cards secured not with a rubber band, but with that colorful slightly tacky tape they use to anchor gauze to the track wound when making blood draws. Yuck!