Fig. 7
From: Damage function for historic paper. Part II: Wear and tear
Accumulation of missing pieces (all sizes) calculated per 100 sheets during the up to 9 challenges (90 treatments). Left bound volumes, right unbound folders. The left y-axis shows values for the DP interval: triangle − DP < 300, the right y-axis for all other DP intervals: circle − 300 < DP < 600, open square − 600 < DP < 900. For DP > 900, no mechanical deterioration was caused. The error bars represent the standard deviation for the average number of missing pieces observed in the individual DP interval