Does paint thinner stain?

Yes, paint thinner is a solvent, and it can stain both clothing and other items, so you have to be careful when you are using it. Depending on the item that was stained, you may be able to at least partially remove any paint thinner stains, with a degreaser. In order to avoid this situation, you should only use as much paint thinner as necessary to do the job at hand, and be careful not to spill it onto your project or clothing. The irony of the whole situation, is that paint thinner is actually used to remove some types of stains, yet it can also cause the very thing that it is designed to get rid of.