If you click the pic, you'll see how it's done.
Click to see how to do it.
Yes, if you slowly bake the phone book for several hours in a just-warm oven, the paper dries out and goes so weak that anyone can rip it, even me.
You could try it too, but I accept no responsibility if you turn your oven up full blast, set fire to the phone book and burn your house down.
For younger readers, an "oven" is a sort of clockwork microwave.
For younger readers, "clockwork" is a kind of ... ach, never mind.