The grade descriptions for paper recycling, as outlined by the Paper Stock Institute, comprise nearly 100 different grades of paper, many of them specialty grades generated by the commercial and industrial sectors. These guidelines are available in printed form and can be made available upon request. However, for most recycling programs for businesses, and the public in general, there are four basic grades which are normally collected and processed by recycling companies. Those four grades are as follows:

1. Cardboard - referred to as OCC (old corrugated cartons) in the PSI guidelines
2. Newspaper - referred to as ONP ( old newspaper)
3. Office Paper - referred to as OP ( office pack)
4. Printer's Waste - this grade is usually broken down into sub grades in the PSI guidelines, but is usually collected and processed as one grade. Companies that generate large volumes will most often generate one or two specific grades of specialty papers.

There are a number of sub-grades of each for these grades of paper. These sub-grades normally reflect the level of contaminants in the material. For instance, the two most used grades of ONPheare called # 8 and #9 ( #9 is pre-consumer newspaper and # 8 is post-consumer). But,the programs designed for recovery and recycling for most companies and the public in general will almost always fall into the four basic grades.