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.

Low Paper Grade

The paper component of label backing sheets is known as glassine, named because it is translucent. The paper fibers are so thin that you can nearly see through the paper. While the most common use of glassine is in release liners, it’s also used in envelopes, food wrappers and pastry bags because it’s smoother than normal paper.

The process of manufacturing glassine involves flattening the paper fibers so that they’re smooth and running in the same direction. Unfortunately, the entire market for paper recycling involves the strength of the fibers, so glassine on its own has a limited recycling market because it’s difficult to extract pulp from the fibers.

Non-Paper Treatment

The second step in making a label backing sheet is to coat it with a release agent, which is what allows us to peel the label or sticker away in the first place.

There are three common release agents for backing sheets: silicone, PET (or #1) plastic resin and polypropylene (or #5) plastic resin. No matter which release agent is used, it would need to be separated during the recycling process in order to reclaim the paper.

Basically, label backing sheets are a low-quality form of paper — that wouldn’t typically be recycled on its own — combined with an unknown coating that is difficult to remove. High processing costs and low material value are the two biggest challenges to recycling, which makes it easy to understand why this product is rarely accepted for recycling.

Corporations Leading the Way

There is a silver lining when it comes to release liner recycling, which is that commercial companies are finding recycling solutions. After all, think about all the products you buy that have a label on them — before that label was applied in a factory, it required a backing.

Avery Dennison, one of the largest label manufacturers in the world, is able to send its used release liners in Europe to a company called PET UK in Scotland. This turns 40 metric tons of annual liner waste into recycled PET for use in new sheets.

Unfortunately, this isn’t likely to lead to a consumer solution for single backing sheets. Avery Dennison bypassed the processing and material issues by providing a large quantity of pre-sorted material, which is a much different situation than trying to recycle a single label backing sheet at the curb.

By Trey Granger

Trey Granger is a former senior waste stream analyst for Earth911.