I decided to try my hand at book repair last night, and learned an important lesson. Wax paper is not plastic – or more specifically, you can’t use wax paper in place of plastic.
The repair was to be rather simple. I had a Collins Concise German-English dictionary which had a cracked spine, and I was going to strengthen it by putting a small line of glue down into the crack. So, I got some Elmer’s craft glue and some wax paper to put into the book while the glue was drying, so as to avoid having excess glue bind the pages together.
The wax paper ended up being a rather nasty mistake. I had read a number of “how to repair books” websites, and thought that I’d read that wax paper could be used for this kind of repair. Apparently, I got wax paper and plastic – like an LP sleeve – mixed up. Wax paper is used in some types of book repair, but blocking craft glue from spreading onto the pages of your book isn’t one of them.
The end result was that this morning, when I opened the dictionary to check out my handiwork, I found the wax paper stuck quite securely down into the spine of the book. I thought that I’d be able to still get it out successfully by pulling on it slowly, but I was wrong. When I finally got it out, it ripped out 4 pages of the dictionary with it, tearing 2 of them quite badly. Not quite the repair I’d had in mind… Oops.
I ended up throwing the dictionary away. I can get a new copy for $10, and while I could have repaired the damage I’d done*, I didn’t really want to be reminded of my stupidity everytime I opened the book.
* Then again, I thought I could repair the cracked spine, too, and we see how that turned out. 
Update: Apparently, I wasn’t 100% wrong. A number of reputable book repair guides say to use wax paper to excess glue from sticking the pages together. The key mistake I made – combining wax paper and craft glue. All of the book repair guides are talking about using PVA glue or wheat paste.