The board and tissue markets have been the two fastest growing segments of the paper industry in the
last 20 years. Globally, the average annual growth from 2000‐2007 has been 4,5% for board and 3,6%
for tissue compared to 1,8% for printing and writing grades [1]. The board production growth is largely
driven by globalization and increased shipping of goods across the globe, whereas the tissue production
growth closely follows the increase in GDP and higher standards of living. The recent economic
recession slowed down this growth, but the industry outlook is still positive in large due to the growth in
the emerging markets [2].
Strength is one of the most important characteristics of paper from the standpoint of both end‐use
characteristics and manufacturing efficiency. Board and tissue are utilized for unrelated purposes that
demand unique characteristics. For example, bending stiffness is required for folding boxboard,
whereas handfeel softness (opposite of stiffness) is desired for toilet paper. Despite the obvious
differences, the fundamentals of paper strength and the chemistries used for strength control are
largely the same for both segments.
The theory and practical aspects of paper strength developments have been extensively reviewed [3‐6].
The key factors of strength development are generally recognized as