When you drop off a bag of clothes at Goodwill, you probably get a kick out of helping others. After all, Goodwill stores are known for being a great source of employment and allowing us to reuse and recycle our clothing. However, the process of what happens to your clothing donation may not be as straightforward as you think.

Here’s how it works. Once workers go through your items, they immediately discard any items that are wet or affected by mildew. The clothing that can be sold is tagged so that workers are able to track how long it spends in the store. The maximum amount of time is four weeks; if an item doesn’t sell in that period, it has to go. But where does it go? You may be surprised to learn that—like luxury stores—Goodwill has outlets. Clothing will often be bundled and sold by the pound at such outlets.

If an item doesn’t sell at the outlet, it then moves onto the auction process. These auctions are often quite exciting, as bidders can get a great value for their dollar. If, however, something fails to sell at auction then it will move onto the next step—a textile recycling organization. In fact, your old donated t-shirt may end up becoming part of a rag—or maybe even a new t-shirt.