Library

You might find it easier to cut out the name labels so that you can handle them better.
The message from the culprit said that, 'you won't have this covered'. If you cover part of the label, will it reveal something? You're not clever enough by 'half'. How might you fold each label?
Can you arrange the three labels so that the revealed words give you an instruction?
By folding each name label in half, or just by covering over half of the squiggles, you will reveal the words: USE THE REWARDS This is your password. All lowercase, all one word