Scientists from academic and the paper industry compile as many aspects of testing properties of paper as possible into a broad reference to help people who plan, specify, and evaluate the physical and mechanical testing of paper material take advantage of the many developments in recent years. An initial essay in each volume discusses the independent invention and widespread use of paper in Mesoamerica beginning sometime before AD 660. The two volumes are paged and indexed separately, but do not seem to be topically distinct. The first edition, Handbook of Physical and Mechanical Testing of Paper and Paperboard appeared in 1983; the second contains 30 chapters, a third of which are new and the others substantially revised, updated, and expanded.