Head Tale

Inspired by Barb's request for the toilet paper rolls pictured in my last entry (unfortunately, that was a borrowed picture from Flickr so I can't help out with that), I'll put out this question…

One of our branches had a sign up requesting empty used Kleenex boxes be donated to the library.  I assumed they were needed for craft projects but it turns out that it was something else, completely unrelated to children's programming. 

Can you guess what they were needed for?