What is the most environmentally-friendly notebook or printer paper?
When you are shopping for paper, whether it's for your office, school, or home, choose paper labeled “100 percent post-consumer recycled content” and “processed chlorine free.”
Paper labeled "100 percent post-consumer recycled" is made from paper recycled in the the blue recycling bin. This is important because you are closing the recycling loop instead of using new trees. Paper that is simply labeled “recycled” is generally made from virgin paper. This paper is made from manufacturers' scraps when the paper is cut. These scraps never reach the consumer and are therefore not part of the recycling loop.
Chlorine is a common bleaching agent used for paper manufacturing, and is harmful to the environment (especially the aquatic environment). Look for paper that is processed chlorine-free.
More information
EPA: Paper Recycling
CalRecycle: Chlorine-free Paper