You might know that stickers don’t belong in the recycling bin, but what about those slick sheets they come on that make peel-off a breeze? They look a little like some types of paper, but does the recycling bin see them that way?

Label backing sheets (officially known as release liners) are a hybrid form of paper found on the back of “my name is…” stickers and address label sheets. While usually the rule is “if it tears, you can recycle it with paper,” this is one exception to the rule. Here’s what makes these backing sheets such an anomaly.